dect/linux-2.6
Archived
14
0
Fork 0
Code Releases Activity

mmc: msm_sdcc: Fix possible circular locking dependency warning

Browse source 
In the context of request processing thread, data mover lock is
acquired after the host lock.  In another context, in the completion
handler of data mover the locks are acquired in the reverse order,
resulting in possible circular lock dependency warning. Hence,
schedule a tasklet to process the dma completion so as to avoid
nested locks.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
This commit is contained in:
Sahitya Tummala 2010-12-08 15:03:03 +05:30 committed by David Brown
parent 50bc0ef42c
commit 62612cf9d9
2 changed files with 36 additions and 16 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

49
drivers/mmc/host/msm_sdcc.c
View file

@ -189,42 +189,40 @@ msmsdcc_dma_exec_func(struct msm_dmov_cmd *cmd)
}
static void
msmsdcc_dma_complete_func(struct msm_dmov_cmd *cmd,
unsigned int result,
struct msm_dmov_errdata *err)
msmsdcc_dma_complete_tlet(unsigned long data)
{
struct msmsdcc_dma_data *dma_data =
container_of(cmd, struct msmsdcc_dma_data, hdr);
struct msmsdcc_host *host = dma_data->host;
struct msmsdcc_host *host = (struct msmsdcc_host *)data;
unsigned long flags;
struct mmc_request *mrq;
struct msm_dmov_errdata err;
spin_lock_irqsave(&host->lock, flags);
host->dma.active = 0;
err = host->dma.err;
mrq = host->curr.mrq;
BUG_ON(!mrq);
WARN_ON(!mrq->data);
if (!(result & DMOV_RSLT_VALID)) {
if (!(host->dma.result & DMOV_RSLT_VALID)) {
pr_err("msmsdcc: Invalid DataMover result\n");
goto out;
}
if (result & DMOV_RSLT_DONE) {
if (host->dma.result & DMOV_RSLT_DONE) {
host->curr.data_xfered = host->curr.xfer_size;
} else {
/* Error or flush */
if (result & DMOV_RSLT_ERROR)
if (host->dma.result & DMOV_RSLT_ERROR)
pr_err("%s: DMA error (0x%.8x)\n",
mmc_hostname(host->mmc), result);
if (result & DMOV_RSLT_FLUSH)
mmc_hostname(host->mmc), host->dma.result);
if (host->dma.result & DMOV_RSLT_FLUSH)
pr_err("%s: DMA channel flushed (0x%.8x)\n",
mmc_hostname(host->mmc), result);
if (err)
pr_err("Flush data: %.8x %.8x %.8x %.8x %.8x %.8x\n",
err->flush[0], err->flush[1], err->flush[2],
err->flush[3], err->flush[4], err->flush[5]);
mmc_hostname(host->mmc), host->dma.result);
pr_err("Flush data: %.8x %.8x %.8x %.8x %.8x %.8x\n",
err.flush[0], err.flush[1], err.flush[2],
err.flush[3], err.flush[4], err.flush[5]);
if (!mrq->data->error)
mrq->data->error = -EIO;
}
@ -273,6 +271,22 @@ out:
return;
}
static void
msmsdcc_dma_complete_func(struct msm_dmov_cmd *cmd,
unsigned int result,
struct msm_dmov_errdata *err)
{
struct msmsdcc_dma_data *dma_data =
container_of(cmd, struct msmsdcc_dma_data, hdr);
struct msmsdcc_host *host = dma_data->host;
dma_data->result = result;
if (err)
memcpy(&dma_data->err, err, sizeof(struct msm_dmov_errdata));
tasklet_schedule(&host->dma_tlet);
}
static int validate_dma(struct msmsdcc_host *host, struct mmc_data *data)
{
if (host->dma.channel == -1)
@ -1118,6 +1132,9 @@ msmsdcc_probe(struct platform_device *pdev)
host->dmares = dmares;
spin_lock_init(&host->lock);
tasklet_init(&host->dma_tlet, msmsdcc_dma_complete_tlet,
(unsigned long)host);
/*
* Setup DMA
*/

3
drivers/mmc/host/msm_sdcc.h
View file

@ -172,6 +172,8 @@ struct msmsdcc_dma_data {
struct msmsdcc_host *host;
int busy; /* Set if DM is busy */
int active;
unsigned int result;
struct msm_dmov_errdata err;
};
struct msmsdcc_pio_data {
@ -235,6 +237,7 @@ struct msmsdcc_host {
int cmdpoll;
struct msmsdcc_stats stats;
struct tasklet_struct dma_tlet;
/* Command parameters */
unsigned int cmd_timeout;
unsigned int cmd_pio_irqmask;