@@ -18,6 +18,7 @@
#include <linux/highmem.h>
#include <linux/mmc/tmio.h>
+#include <linux/mutex.h>
#include <linux/pagemap.h>
#include <linux/spinlock.h>
@@ -73,8 +74,11 @@ struct tmio_mmc_host {
/* Track lost interrupts */
struct delayed_work delayed_reset_work;
- spinlock_t lock;
+ struct work_struct done;
+
+ spinlock_t lock; /* protect host private data */
unsigned long last_req_ts;
+ struct mutex ios_lock; /* protect set_ios() context */
};
int tmio_mmc_host_probe(struct tmio_mmc_host **host,
@@ -250,10 +250,16 @@ static void tmio_mmc_reset_work(struct work_struct *work)
/* called with host->lock held, interrupts disabled */
static void tmio_mmc_finish_request(struct tmio_mmc_host *host)
{
- struct mmc_request *mrq = host->mrq;
+ struct mmc_request *mrq;
+ unsigned long flags;
- if (!mrq)
+ spin_lock_irqsave(&host->lock, flags);
+
+ mrq = host->mrq;
+ if (IS_ERR_OR_NULL(mrq)) {
+ spin_unlock_irqrestore(&host->lock, flags);
return;
+ }
host->cmd = NULL;
host->data = NULL;
@@ -262,11 +268,18 @@ static void tmio_mmc_finish_request(struct tmio_mmc_host *host)
cancel_delayed_work(&host->delayed_reset_work);
host->mrq = NULL;
+ spin_unlock_irqrestore(&host->lock, flags);
- /* FIXME: mmc_request_done() can schedule! */
mmc_request_done(host->mmc, mrq);
}
+static void tmio_mmc_done_work(struct work_struct *work)
+{
+ struct tmio_mmc_host *host = container_of(work, struct tmio_mmc_host,
+ done);
+ tmio_mmc_finish_request(host);
+}
+
/* These are the bitmasks the tmio chip requires to implement the MMC response
* types. Note that R1 and R6 are the same in this scheme. */
#define APP_CMD 0x0040
@@ -433,7 +446,7 @@ void tmio_mmc_do_data_irq(struct tmio_mmc_host *host)
BUG();
}
- tmio_mmc_finish_request(host);
+ schedule_work(&host->done);
}
static void tmio_mmc_data_irq(struct tmio_mmc_host *host)
@@ -523,7 +536,7 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host,
tasklet_schedule(&host->dma_issue);
}
} else {
- tmio_mmc_finish_request(host);
+ schedule_work(&host->done);
}
out:
@@ -573,7 +586,8 @@ irqreturn_t tmio_mmc_irq(int irq, void *devid)
if (ireg & (TMIO_STAT_CARD_INSERT | TMIO_STAT_CARD_REMOVE)) {
tmio_mmc_ack_mmc_irqs(host, TMIO_STAT_CARD_INSERT |
TMIO_STAT_CARD_REMOVE);
- mmc_detect_change(host->mmc, msecs_to_jiffies(100));
+ if (!work_pending(&host->mmc->detect.work))
+ mmc_detect_change(host->mmc, msecs_to_jiffies(100));
goto out;
}
@@ -703,6 +717,8 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
struct tmio_mmc_data *pdata = host->pdata;
unsigned long flags;
+ mutex_lock(&host->ios_lock);
+
spin_lock_irqsave(&host->lock, flags);
if (host->mrq) {
if (IS_ERR(host->mrq)) {
@@ -718,6 +734,8 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
host->mrq->cmd->opcode, host->last_req_ts, jiffies);
}
spin_unlock_irqrestore(&host->lock, flags);
+
+ mutex_unlock(&host->ios_lock);
return;
}
@@ -771,6 +789,8 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
current->comm, task_pid_nr(current),
ios->clock, ios->power_mode);
host->mrq = NULL;
+
+ mutex_unlock(&host->ios_lock);
}
static int tmio_mmc_get_ro(struct mmc_host *mmc)
@@ -867,9 +887,11 @@ int __devinit tmio_mmc_host_probe(struct tmio_mmc_host **host,
tmio_mmc_enable_sdio_irq(mmc, 0);
spin_lock_init(&_host->lock);
+ mutex_init(&_host->ios_lock);
/* Init delayed work for request timeouts */
INIT_DELAYED_WORK(&_host->delayed_reset_work, tmio_mmc_reset_work);
+ INIT_WORK(&_host->done, tmio_mmc_done_work);
/* See if we also get DMA */
tmio_mmc_request_dma(_host, pdata);
@@ -917,6 +939,7 @@ void tmio_mmc_host_remove(struct tmio_mmc_host *host)
pm_runtime_get_sync(&pdev->dev);
mmc_remove_host(host->mmc);
+ cancel_work_sync(&host->done);
cancel_delayed_work_sync(&host->delayed_reset_work);
tmio_mmc_release_dma(host);
Calling mmc_request_done() under a spinlock with interrupts disabled leads to a recursive spin-lock on request retry path and to scheduling in atomic context. This patch fixes both these problems by moving mmc_request_done() to the scheduler workqueue. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> --- This is a bug-fix: without it the system Oopses with LOCKDEP enabled, so, it should really go in 3.0. OTOH it is pretty intrusine and non-trivial, so, reviews and tests are highly appreciated! Also, unfortunately, I wasn't able to test it well enough with SDIO, because the driver for the only SDIO card, that I have, reproducibly crashes the kernel: http://www.spinics.net/lists/kernel/msg1203334.html So, mainly tested with SD-cards and only lightly with SDIO. v3: no functional changes, only updated on top of current mmc-next v2: 1. added a mutex to properly complete each .set_ios() call instead of returning an error, when racing with another one. 2. oritect data inside tmio_mmc_finish_request() 3. don't reschedule card detection, if one is already pending drivers/mmc/host/tmio_mmc.h | 6 +++++- drivers/mmc/host/tmio_mmc_pio.c | 35 +++++++++++++++++++++++++++++------ 2 files changed, 34 insertions(+), 7 deletions(-)