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spi/pl022: move device disable to workqueue thread 

Moves the disabling of the device and clocks to the same thread in
which the device and clocks are enabled. This avoids SMP issues where
the device can be enabled for a transfer by one thread and then
disabled by the completion of the previous transfer in another thread.

Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Chris Blair <chris.blair@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Chris Blair 2011-11-04 07:43:41 +00:00 committed by Linus Walleij
parent 4ca9fb46d8
commit d4b6af2e0e
1 changed files with 16 additions and 9 deletions
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25
drivers/spi/spi-pl022.c
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@ -512,8 +512,6 @@ static void giveback(struct pl022 *pl022)
msg->state = NULL;
if (msg->complete)
msg->complete(msg->context);
/* This message is completed, so let's turn off the clocks & power */
pm_runtime_put(&pl022->adev->dev);
}
/**
@ -1509,14 +1507,18 @@ static void pump_messages(struct work_struct *work)
struct pl022 *pl022 =
container_of(work, struct pl022, pump_messages);
unsigned long flags;
bool was_busy = false;
/* Lock queue and check for queue work */
spin_lock_irqsave(&pl022->queue_lock, flags);
if (list_empty(&pl022->queue) || !pl022->running) {
if (pl022->busy)
pm_runtime_put(&pl022->adev->dev);
pl022->busy = false;
spin_unlock_irqrestore(&pl022->queue_lock, flags);
return;
}
/* Make sure we are not already running a message */
if (pl022->cur_msg) {
spin_unlock_irqrestore(&pl022->queue_lock, flags);
@ -1527,7 +1529,10 @@ static void pump_messages(struct work_struct *work)
list_entry(pl022->queue.next, struct spi_message, queue);
list_del_init(&pl022->cur_msg->queue);
pl022->busy = true;
if (pl022->busy)
was_busy = true;
else
pl022->busy = true;
spin_unlock_irqrestore(&pl022->queue_lock, flags);
/* Initial message state */
@ -1537,12 +1542,14 @@ static void pump_messages(struct work_struct *work)
/* Setup the SPI using the per chip configuration */
pl022->cur_chip = spi_get_ctldata(pl022->cur_msg->spi);
/*
* We enable the core voltage and clocks here, then the clocks
* and core will be disabled when giveback() is called in each method
* (poll/interrupt/DMA)
*/
pm_runtime_get_sync(&pl022->adev->dev);
if (!was_busy)
/*
* We enable the core voltage and clocks here, then the clocks
* and core will be disabled when this workqueue is run again
* and there is no more work to be done.
*/
pm_runtime_get_sync(&pl022->adev->dev);
restore_state(pl022);
flush(pl022);