According to ehci spec 4.10.2, Advance Queue
If the fetched qTD has its Active bit set to a zero, the
host controller aborts the queue advance and follows the
queue head's horizontal pointer to the next schedule data
structure.
the 'qtd' will be linked into qh hardware queue after the line
below
*dummy = *qtd;
is executed and observed by EHCI HC, but EHCI HC won't have chance to
fetch the qtd descriptor pointed by 'qtd' in qh_append_tds until the
line below
dummy->hw_token = token; #set Active bit here
is executed by CPU and observed by EHCI HC.
There is already one 'wmb' to order writing to 'dummy'/'qtd' descriptors
and writing 'token' to 'dummy' descriptor(set Active bit), so the 1st
wmb is not needed and can be removed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Obviously, ZLP is only required for transfer of OUT direction,
so just take same policy with UHCI for ZLP packet.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
qh_refresh is always called when the qh is idle and has not been
linked into hardware queue, so EHCI will not access overlay of
the qh at this time. Just before linking qh into hardware queue, there
has already one wmb to order writing qh descriptor and writing dma
address of the qh into hardware queue, so HC can always see
up-to-date qh descriptor once the qh is fetched with its dma address
by EHCI.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1483) improves the ehci-hcd driver family by getting rid
of the reliance on the hcd->state variable. It has no clear owner and
it isn't protected by the usual HCD locks. In its place, the patch
adds a new, private ehci->rh_state field to record the state of the
root hub.
Along the way, the patch removes a couple of lines containing
redundant assignments to the state variable. Also, the QUIESCING
state simply gets changed to the RUNNING state, because the driver
doesn't make any distinction between them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1480) fixes a rather obscure bug in ehci-hcd. The
qh_update() routine needs to know the number and direction of the
endpoint corresponding to its QH argument. The number can be taken
directly from the QH data structure, but the direction isn't stored
there. The direction is taken instead from the first qTD linked to
the QH.
However, it turns out that for interrupt transfers, qh_update() gets
called before the qTDs are linked to the QH. As a result, qh_update()
computes a bogus direction value, which messes up the endpoint toggle
handling. Under the right combination of circumstances this causes
usb_reset_endpoint() not to work correctly, which causes packets to be
dropped and communications to fail.
Now, it's silly for the QH structure not to have direct access to all
the descriptor information for the corresponding endpoint. Ultimately
it may get a pointer to the usb_host_endpoint structure; for now,
adding a copy of the direction flag solves the immediate problem.
This allows the Spyder2 color-calibration system (a low-speed USB
device that sends all its interrupt data packets with the toggle set
to 0 and hance requires constant use of usb_reset_endpoint) to work
when connected through a high-speed hub. Thanks to Graeme Gill for
supplying the hardware that allowed me to track down this bug.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Graeme Gill <graeme@argyllcms.com>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1477) fixes a problem affecting a few types of EHCI
controller. Contrary to what one might expect, these controllers
automatically stop their internal frame counter when no ports are
enabled. Since ehci-hcd currently relies on the frame counter for
determining when it should unlink QHs from the async schedule, those
controllers run into trouble: The frame counter stops and the QHs
never get unlinked.
Some systems have also experienced other problems traced back to
commit b963801164 (USB: ehci-hcd unlink
speedups), which made the original switch from using the system clock
to using the frame counter. It never became clear what the reason was
for these problems, but evidently it is related to use of the frame
counter.
To fix all these problems, this patch more or less reverts that commit
and goes back to using the system clock. But this can't be done
cleanly because other changes have since been made to the scan_async()
subroutine. One of these changes involved the tricky logic that tries
to avoid rescanning QHs that have already been seen when the scanning
loop is restarted, which happens whenever an URB is given back.
Switching back to clock-based unlinks would make this logic even more
complicated.
Therefore the new code doesn't rescan the entire async list whenever a
giveback occurs. Instead it rescans only the current QH and continues
on from there. This requires the use of a separate pointer to keep
track of the next QH to scan, since the current QH may be unlinked
while the scanning is in progress. That new pointer must be global,
so that it can be adjusted forward whenever the _next_ QH gets
unlinked. (uhci-hcd uses this same trick.)
Simplification of the scanning loop removes a level of indentation,
which accounts for the size of the patch. The amount of code changed
is relatively small, and it isn't exactly a reversion of the
b963801164 commit.
This fixes Bugzilla #32432.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@kernel.org>
Tested-by: Matej Kenda <matejken@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1466) speeds up processing of ehci-hcd's periodic list.
The existing code will pointlessly rescan an interrupt endpoint queue
each time it encounters the queue's QH in the periodic list, which can
happen quite a few times if the endpoint's period is low. On some
embedded systems, this useless overhead can waste so much time that
the driver falls hopelessly behind and loses events.
The patch introduces a "periodic_stamp" variable, which gets
incremented each time scan_periodic() runs and each time the scan
advances to a new frame. If the corresponding stamp in an interrupt
QH is equal to the current periodic_stamp, we assume the QH has
already been scanned and skip over it. Otherwise we scan the QH as
usual, and if none of its URBs have completed then we store the
current periodic_stamp in the QH's stamp, preventing it from being
scanned again.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A Synopsys USB core used in various SoCs has a bug which might cause
that the host controller not issuing ping.
When software uses the Doorbell mechanism to remove queue heads, the
host controller still has references to the removed queue head even
after indicating an Interrupt on Async Advance. This happens if the last
executed queue head's Next Link queue head is removed.
Consequences of the defect:
The Host controller fetches the removed queue head, using memory that
would otherwise be deallocated.This results in incorrect transactions on
both the USB and system memory. This may result in undefined behavior.
Workarounds:
1) If no queue head is active (no Status field's Active bit is set)
after removing the queue heads, the software can write one of the valid
queue head addresses to the ASYNCLISTADDR register and deallocate the
removed queue head's memory after 2 microframes.
If one or more of the queue heads is active (the Active bit is set in
the Status field) after removing the queue heads, the software can delay
memory deallocation after time X, where X is the time required for the
Host Controller to go through all the queue heads once. X varies with
the number of queue heads and the time required to process periodic
transactions: if more periodic transactions must be performed, the Host
Controller has less time to process asynchronous transaction processing.
2) Do not use the Doorbell mechanism to remove the queue heads. Disable
the Asynchronous Schedule Enable bit instead.
The bug has been discussed on the linux-usb-devel mailing-list
four years ago, the original thread can be found here:
http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg45345.html
This patch implements the first workaround as suggested by David Brownell.
The built-in USB host controller of the Atheros AR7130/AR7141/AR7161 SoCs
requires this to work properly.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1458) fixes a problem affecting ultra-reliable systems:
When hardware failover of an EHCI controller occurs, the data
structures do not get released correctly. This is because the routine
responsible for removing unused QHs from the async schedule assumes
the controller is running properly (the frame counter is used in
determining how long the QH has been idle) -- but when a failover
causes the controller to be electronically disconnected from the PCI
bus, obviously it stops running.
The solution is simple: Allow scan_async() to remove a QH from the
async schedule if it has been idle for long enough _or_ if the
controller is stopped.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-Tested-by: Dan Duval <dan.duval@stratus.com>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1453) fixes a long-standing bug in the ehci-hcd driver.
There is no need to set the Halt bit in the overlay region for an
unlinked or blocked QH. Contrary to what the comment says, setting
the Halt bit does not cause the QH to be patched later; that decision
(made in qh_refresh()) depends only on whether the QH is currently
pointing to a valid qTD. Likewise, setting the Halt bit does not
prevent completions from activating the QH while it is "stopped"; they
are prevented by the fact that qh_completions() temporarily changes
qh->qh_state to QH_STATE_COMPLETING.
On the other hand, there are circumstances in which the QH will be
reactivated _without_ being patched; this happens after an URB beyond
the head of the queue is unlinked. Setting the Halt bit will then
cause the hardware to see the QH with both the Active and Halt bits
set, an invalid combination that will prevent the queue from
advancing and may even crash some controllers.
Apparently the only reason this hasn't been reported before is that
unlinking URBs from the middle of a running queue is quite uncommon.
However Test 17, recently added to the usbtest driver, does exactly
this, and it confirms the presence of the bug.
In short, there is no reason to set the Halt bit for an unlinked or
blocked QH, and there is a very good reason not to set it. Therefore
the code that sets it is removed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Andiry Xu <andiry.xu@amd.com>
CC: David Brownell <david-b@pacbell.net>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
With pre-release GCC-4.6, we get a 'set but not used' warning when
EHCI_URB_TRACE is not set because we set the qtd variable without
using it.
Rearrange the statements so that we only set qtd if it will be used.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1393) converts several of the single-bit fields in
struct usb_hcd to atomic flags. This is for safety's sake; not all
CPUs can update bitfield values atomically, and these flags are used
in multiple contexts.
The flag fields that are set only during registration or removal can
remain as they are, since non-atomic accesses at those times will not
cause any problems.
(Strictly speaking, the authorized_default flag should become atomic
as well. I didn't bother with it because it gets changed only via
sysfs. It can be done later, if anyone wants.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Change the type of the URB's 'sg' pointer from a usb_sg_request to
a scatterlist. This allows drivers to submit scatter-gather lists
without using the usb_sg_wait() interface. It has the added benefit
of removing the typecasts that were added as part of patch as1368 (and
slightly decreasing the number of pointer dereferences).
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1320) fixes two problems related to interrupt-URB
scheduling in ehci-hcd.
URBs with an interval of 2 or 4 microframes aren't handled.
For the time being, the patch reduces to interval to 1 uframe.
URBs are constrained to have an interval no larger than 1024
frames by usb_submit_urb(). But some EHCI controllers allow
use of a schedule as short as 256 frames; for these
controllers we may have to decrease the interval to the
actual schedule length.
The second problem isn't very significant since few devices expose
interrupt endpoints with an interval larger than 256 frames. But the
first problem is critical; it will prevent the kernel from working
with devices having interrupt intervals of 2 or 4 uframes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Tested-by: Glynn Farrow <farrowg@sg.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1300) adds native scatter-gather support to ehci-hcd.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1304) fixes a regression in ehci-hcd. Evidently some
hubs don't handle Clear-TT-Buffer requests correctly, so we should
avoid sending them when they don't appear to be absolutely necessary.
The reported symptom is that output on a downstream audio device cuts
out because the hub stops relaying isochronous packets.
The patch prevents Clear-TT-Buffer requests from being sent following
a STALL handshake. In theory a STALL indicates either that the
downstream device sent a STALL or that no matching TT buffer could be
found. In either case, the transfer is completed and the TT buffer
does not remain busy, so it doesn't need to be cleared.
Also, the patch fixes a minor flaw in the code that actually sends the
Clear-TT-Buffer requests. Although the pipe direction isn't really
used for control transfers, it should be a Send rather than a Receive.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Javier Kohen <jkohen@users.sourceforge.net>
CC: David Brownell <david-b@pacbell.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1281) changes the way ehci-hcd deschedules interrupt
QHs, copying the approach used for async QHs. The caller is no longer
responsible for rescheduling the QH if its queue is non-empty; instead
the reschedule is done directly by intr_deschedule(), after calling
qh_completions(). This is exactly the same as how end_unlink_async()
works.
ehci_urb_dequeue() and intr_deschedule() now correctly handle the case
where they are called while another interrupt URB for the same QH is
being given back. This was a surprisingly large blind spot. And
scan_periodic() now respects the new needs_rescan flag.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1280) fixes an obscure bug in ehci-hcd's dequeuing logic
for async URBs. If a later URB is unlinked and the completion
routine unlinks an earlier URB, then the earlier URB won't be given
back in a timely manner because the endpoint queue isn't rescanned as
it should be.
Similar bugs occur if an endpoint is reset or a halt is cleared while
a completion routine is running, because the subroutines don't test
for the COMPLETING state.
All these problems are solved by adding a new needs_rescan flag to the
ehci_qh structure. If the flag is set while scanning through an idle
QH, the scan will be repeated. If the QH isn't idle then an unlink
cycle will be initiated, and the proper action will be taken when it
becomes idle.
Also, an unnecessary test is removed from qh_link_async(): That
routine is never called if the QH's state isn't IDLE.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The ehci_qh structure merged hw and sw together which is not good:
1. More and more items are being added into ehci_qh, the ehci_qh software
part are unnecessary to be allocated in DMA qh_pool.
2. If HCD has local SRAM, the sw part will consume it too, and it won't
bring any benefit.
3. For non-cache-coherence system, the entire ehci_qh is uncachable, actually
we only need the hw part to be uncacheable. Spliting them will let the sw
part to be cacheable.
Signed-off-by: Alek Du <alek.du@intel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
CC: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1274) simplifies the counting of transaction-error
retries. Now we will count up from 0 to QH_XACTERR_MAX instead of
down from QH_XACTERR_MAX to 0.
The patch also fixes a small bug: qh->xacterr was not getting
initialized for interrupt endpoints.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1273) fixes two(!) bugs introduced by the new
Clear-TT-Buffer implementation in ehci-hcd.
It is now possible for an idle QH to have some URBs on its
queue -- this will happen if a Clear-TT-Buffer is pending for
the QH's endpoint. Consequently we should not issue a warning
when someone tries to unlink an URB from an idle QH; instead
we should process the request immediately.
The refcounts for QHs could get messed up, because
submit_async() would increment the refcount when calling
qh_link_async() and qh_link_async() would then refuse to link
the QH into the schedule if a Clear-TT-Buffer was pending.
Instead we should increment the refcount only when the QH
actually is added to the schedule. The current code tries to
be clever by leaving the refcount alone if an unlink is
immediately followed by a relink; the patch changes this to an
unconditional decrement and increment (although they occur in
the opposite order).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Tested-by: Manuel Lauss <manuel.lauss@gmail.com>
Tested-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1257) revises the way ehci-hcd detects STALLs. The
logic is a little peculiar because there's no hardware status bit
specifically meant to indicate a STALL. You just have to guess that a
STALL was received if the BABBLE bit (which is fatal) isn't set and
the transfer stopped before all its retries were used up.
The existing code doesn't do this properly, because it tests for MMF
(Missed MicroFrame) and DBE (Data Buffer Error) before testing the
retry counter. Thus, if a transaction gets either MMF or DBE the
corresponding flag is set and the transaction is retried. If the
second attempt receives a STALL then -EPIPE is the correct return
value. But the existing code would see the MMF or DBE flag instead
and return -EPROTO, -ENOSR, or -ECOMM.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1256) changes ehci-hcd and all the other drivers in the
EHCI family to make use of the new clear_tt_buffer callbacks. When a
Clear-TT-Buffer request is in progress for a QH, the QH is not allowed
to be linked into the async schedule until the request is finished.
At that time, if there are any URBs queued for the QH, it is linked
into the async schedule.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1255) updates the interface for calling
usb_hub_clear_tt_buffer(). Even the name of the function is changed!
When an async URB (i.e., Control or Bulk) going through a high-speed
hub to a non-high-speed device is cancelled or fails, the hub's
Transaction Translator buffer may be left busy still trying to
complete the transaction. The buffer has to be cleared; that's what
usb_hub_clear_tt_buffer() does.
It isn't safe to send any more URBs to the same endpoint until the TT
buffer is fully clear. Therefore the HCD needs to be told when the
Clear-TT-Buffer request has finished. This patch adds a callback
method to struct hc_driver for that purpose, and makes the hub driver
invoke the callback at the proper time.
The patch also changes a couple of names; "hub_tt_kevent" and
"tt.kevent" now look rather antiquated.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is an update to the "usb-ehci-update-toggle-state-for-linked-qhs"
patch. Since an HCD's endpoint_reset method can be called in
interrupt context, it mustn't assume that interrupts are enabled or
that it can sleep.
So we revert to the original way of refreshing QHs' toggle bits. Now
the endpoint_reset method merely clears the toggle flag in the device
structure (as was done before) and starts an async QH unlink. When the
QH is linked again, after the unlink finishes and an URB is queued,
the qh_refresh() routine will update the QH's toggle bit.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: David <david@unsolicited.net>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1245) fixes a bug in ehci-hcd. When an URB is queued
for an endpoint whose QH is already in the LINKED state, the QH
doesn't get refreshed. As a result, if usb_clear_halt() was called
during the time that the QH was linked but idle, the data toggle value
in the QH doesn't get reset.
The symptom is that after a clear_halt, data gets lost and transfers
time out. This problem is starting to show up now because the
"ehci-hcd unlink speedups" patch causes QHs with no queued URBs to
remain linked for a suitable time.
The patch utilizes the new endpoint_reset mechanism to fix the
problem. When an endpoint is reset, the new method forcibly unlinks
the QH (if necessary) and safely updates the toggle value. This
allows qh_update() to be simplified and avoids using usb_device's
toggle bits in a rather unintuitive way.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Tested-by: David <david@unsolicited.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix ehci printk formats:
drivers/usb/host/ehci-q.c:351: warning: format '%d' expects type 'int', but argument 4 has type 'size_t'
drivers/usb/host/ehci-q.c:351: warning: format '%d' expects type 'int', but argument 5 has type 'size_t'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1204) adds a software retry mechanism to ehci-hcd. It
gets invoked when the driver encounters transaction errors on an
asynchronous endpoint. On many systems, hardware deficiencies cause
such errors to occur if one device is unplugged while the host is
communicating with another device. With the patch, the failed
transactions are retried and generally succeed the second or third
time through.
This is based on code originally written by Koichiro Saito.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested by: Koichiro Saito <Saito.Koichiro@adniss.jp>
CC: David Brownell <david-b@pacbell.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1225) fixes a bug in ehci-hcd. The condition for
whether unlinked QHs can become IDLE should not be that the controller
is halted, but rather that the controller isn't running. In other
words when the root hub is suspended, the hardware doesn't own any
QHs.
This fixes a problem that can show up during hibernation: If a QH is
only partially unlinked when the root hub is frozen, then when the
root hub is thawed the QH won't be in the IDLE state. As a result it
can't be used properly for new URB submissions.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Brandon Philips <brandon@ifup.org>
Tested-by: Brandon Philips <brandon@ifup.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If you are using linked lists for queues list_splice() will not do what
you would expect even if you use the elements passed reversed. We need
to handle these differently. We add list_splice_tail() and
list_splice_tail_init().
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch fixes some performance bugs observed with some workloads
when unlinking EHCI queue header (QH) descriptors from the async ring
(control/bulk schedule).
The mechanism intended to defer unlinking an empty QH (so there is no
penalty in common cases where it's quickly reused) was not working as
intended. Sometimes the unlink was scheduled:
- too quickly ... which can be a *strong* negative effect, since
that QH becomes unavailable for immediate re-use;
- too slowly ... wasting DMA cycles, usually a minor issue except
for increased bus contention and power usage;
Plus there was an extreme case of "too slowly": a logical error in the
IAA watchdog-timer conversion meant that sometimes the unlink never
got scheduled.
The fix replaces a simple counter with a timestamp derived from the
controller's 8 KHz microframe counter, and adjusts the timer usage
for some issues associated with HZ being less than 8K.
(Based on a patch originally by Alan Stern, and good troubleshooting
from Leonid.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Leonid <leonidv11@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* endianness annotations
* endianness fixes
* missing get_unaligned/put_unaligned
It's pretty much all over the place, changes to different files are independent.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Serial-parts-Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Simplify processing of completed qtds, and correct handling of short
reads, by removing two state variables:
- "qtd_status" wasn't needed. The current URB's status is either
OK (-EINPROGRESS) or some fault status. Once a fault appears,
the queue halts and any later QTDs are immediately removed, so
no temporary status is needed. (Or for typical short reads,
it's not treated as a fault, so no queue halt is needed.)
- "do_status" was erroneous. Because of how the queue is set up,
short control reads can (and should!) be treated like full size
reads, and cleaned up the usual way. The status stage will be
executed transparently, and usbcore handles the choice of whether
to report this status as unexected.
The "do_status" problem caused a rather perplexing timing-dependent
problem with usbtest case 10. Sometimes it would make the controller
skip a dozen transactions while (wrongly) trying to clean up after a
short transfer. Fortunately, removing a dcache contention issue made
this become trivial to reproduce (on one test rig), so enough clues
finally presented themselves ... I think this has been around for a
very long time, but was worsened by recent urb->status changes.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Provide better comments about qh_completions() and QTD handling.
That code can be *VERY* confusing, since it's evolved over a few
years to cope with both hardware races and silicon quirks.
Remove two unlikely() annotations that match the GCC defaults
(and are thus pointless); add an "else" to highlight code flow.
This patch doesn't change driver behavior.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This teaches EHCI how to to work around bugs in certain high speed
devices, by accomodating "bulk" packets that exceed the 512 byte
constant value required by the USB 2.0 specification. (Have a
look at section 5.8.3, paragraphs 1 and 3.)
It also makes the descriptor parsing code warn when it encounters
such bugs. (We've had reports of maybe two or three such devices,
all pretty recent.)
Such devices are nonconformant. The proper fix is have the vendors
of those devices do the simple, obvious, and correct thing ... which
will let them be used with USB hosts that don't have workarounds for
this particular vendor bug. But unless/until they do, we can at least
have one of the high speed HCDs work with such buggy devices.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB: ehci: Fixes completion for multi-qtd URB the short read case
When use of urb->status in the EHCI driver was reworked last August
(commit 14c04c0f88), a bug was inserted
in the handling of early completion for bulk transactions that need
more than one qTD (e.g. more than 20KB in one URB).
This patch resolves that problem by ensuring that the early completion
status is preserved until the URB is handed back to its submitter,
instead of resetting it after each qTD.
Signed-off-by: Misha Zhilin <misha@epiphan.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Kernel bugzilla entry #9569 reports a potential OOPS in some code
supporting the integrated root hub TT support used on ARC/TDI
derived cores. (This seems to have been a longstanding issue.)
This patch cleans up usage of urb->dev->tt to avoid that potential
oops and also fixes some overly long lines.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1028) was mostly written by David Brownell; I made only
a few changes (extra log info and a small bug fix -- which might
account for why David's version had to be reverted). It adds a new
watchdog timer to the ehci-hcd driver to be used exclusively for
detecting lost or missing IAA notifications.
Previously a shared timer had been used, which may have led to some
problems as reported by Christian Hoffmann.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as979) removes the last vestiges of urb->status from the
host controller drivers and the root-hub emulator. Now the field
doesn't get set until just before the URB's completion routine is
called.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as974) reorganizes the way ehci-hcd sets urb->status. It
now keeps the information in a local variable until the last moment.
The patch also simplifies the handling of -EREMOTEIO, since the only
use of that code is to set the do_status flag.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as970) adds a new urb->unlinked field, which is used to
store the status of unlinked URBs since we can't use urb->status for
that purpose any more. To help simplify the HCDs, usbcore will check
urb->unlinked before calling the completion handler; if the value is
set it will automatically override the status reported by the HCD.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as969) continues the ongoing changes to the way HCDs
report URB statuses. The programming interface has been simplified by
making usbcore responsible for clearing urb->hcpriv and for setting
-EREMOTEIO status when an URB with the URB_SHORT_NOT_OK flag ends up
as a short transfer.
By moving the work out of the HCDs, this removes a fair amount of
repeated code.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as954) implements a suggestion of David Brownell's. Now
the host controller drivers are responsible for linking and unlinking
URBs to/from their endpoint queues. This eliminates the possiblity of
strange situations where usbcore thinks an URB is linked but the HCD
thinks it isn't. It also means HCDs no longer have to check for URBs
being dequeued before they were fully enqueued.
In addition to the core changes, this requires changing every host
controller driver and the root-hub URB handler. For the most part the
required changes are fairly small; drivers have to call
usb_hcd_link_urb_to_ep() in their urb_enqueue method,
usb_hcd_check_unlink_urb() in their urb_dequeue method, and
usb_hcd_unlink_urb_from_ep() before giving URBs back. A few HCDs make
matters more complicated by the way they split up the flow of control.
In addition some method interfaces get changed. The endpoint argument
for urb_enqueue is now redundant so it is removed. The unlink status
is required by usb_hcd_check_unlink_urb(), so it has been added to
urb_dequeue.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
CC: Olav Kongas <ok@artecdesign.ee>
CC: Tony Olech <tony.olech@elandigitalsystems.com>
CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit 196705c9bb. It was
reported to cause a regression by Daniel Exner, and Arjan van de Ven
points out that we actually already have infrastructure in place for
setting limits on acceptable DMA latency that would be the much more
correct fix for the problem with some Broadcom EHCI controllers.
Fixed up trivial conflicts due to the changes to support big-endian host
controller descriptors in drivers/usb/host/{ehci-sched.c,ehci.h}.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch implements supports for EHCI controllers whose in-memory
data structures are represented in big-endian format. This is needed
(unfortunately) for the AMCC PPC440EPx SoC EHCI controller; the EHCI
spec doesn't specify little-endian format, although that's what most
other implementations use.
The guts of the patch are to introduce the hc32 type and change all
references from le32 to hc32. All access routines are converted from
cpu_to_le32(...) to cpu_to_hc32(ehci, ...) and similar for the other
"direction". (This is the same approach used with OHCI.)
David fixed:
Whitespace fixes; refresh against ehci cpufreq patch; move glue
for that PPC driver to the patch adding it; fix free symbol
capture bugs in modified "constant" macros; and make "hc32" etc
be "le32" unless we really need the BE options, so "sparse" can
do some real good.
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
EHCI controllers that don't cache enough microframes can get MMF errors
when CPU frequency changes occur between the start and completion of
split interrupt transactions, due to delays in reading main memory
(caused by CPU cache snoop delays).
This patch adds a cpufreq notifier to the EHCI driver that will
inactivate split interrupt transactions during frequency transitions.
It was tested on Intel ICH7 and Serverworks/Broadcom HT1000 EHCI
controllers.
Signed-off-by: Stuart Hayes <stuart_hayes@dell.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch implements supports for EHCI controllers whose MMIO
registers are big endian and enables that functionality for
the Toshiba SCC chip. It does _not_ add support for big endian
in-memory data structures as this is not needed for that chip
and I hope it will never be.
The guts of the patch are to convert readl(...) to
ehci_readl(ehci, ...) and similarly for register writes.
Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts 26f953fd88 which caused
resume problems on the mac mini.
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
