sdhci_request() and sdhci_card_event() read the cd-gpio via
mmc_gpio_get_cd(), which can sleep, while holding host->lock.
This may result in the following BUG:
BUG: spinlock wrong CPU on CPU#2, kworker/u8:16/4296
lock: 0xea6b9c80, .magic: dead4ead, .owner: kworker/u8:16/4296, .owner_cpu: 0
CPU: 2 PID: 4296 Comm: kworker/u8:16 Tainted: G C 3.10.18 #137
Workqueue: kmmcd mmc_rescan
[<8020cf8c>] (unwind_backtrace+0x0/0x118) from [<8020a0c8>]
(show_stack+0x20/0x24)
[<8020a0c8>] (show_stack+0x20/0x24) from [<8075e5b8>] (dump_stack+0x20/0x28)
[<8075e5b8>] (dump_stack+0x20/0x28) from [<804184a8>] (spin_dump+0x80/0x94)
[<804184a8>] (spin_dump+0x80/0x94) from [<804184e8>] (spin_bug+0x2c/0x30)
[<804184e8>] (spin_bug+0x2c/0x30) from [<80418790>]
(do_raw_spin_unlock+0x94/0xd4)
[<80418790>] (do_raw_spin_unlock+0x94/0xd4) from [<80761a44>]
(_raw_spin_unlock_irqrestore+0x1c/0x24)
[<80761a44>] (_raw_spin_unlock_irqrestore+0x1c/0x24) from [<805ff66c>]
(sdhci_request+0x1c8/0x1d0)
[<805ff66c>] (sdhci_request+0x1c8/0x1d0) from [<805ebb5c>]
(mmc_start_request+0xec/0xf4)
[<805ebb5c>] (mmc_start_request+0xec/0xf4) from [<805ebcbc>]
(mmc_wait_for_req+0x80/0xf4)
...
Read the cd-gpio before acquiring the spinlock instead.
Signed-off-by: Andrew Bresticker <abres...@chromium.org>
---
drivers/mmc/host/sdhci.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 04a5e25..328b250 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1340,6 +1340,7 @@ static void sdhci_request(struct mmc_host *mmc, struct
mmc_request *mrq)
u32 tuning_opcode;
host = mmc_priv(mmc);
+ present = mmc_gpio_get_cd(host->mmc);
sdhci_runtime_pm_get(host);
@@ -1371,7 +1372,6 @@ static void sdhci_request(struct mmc_host *mmc, struct
mmc_request *mrq)
* zero: cd-gpio is used, and card is removed
* one: cd-gpio is used, and card is present
*/
- present = mmc_gpio_get_cd(host->mmc);
if (present < 0) {
/* If polling, assume that the card is always present. */
if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
@@ -2082,15 +2082,16 @@ static void sdhci_card_event(struct mmc_host *mmc)
{
struct sdhci_host *host = mmc_priv(mmc);
unsigned long flags;
+ int present;
/* First check if client has provided their own card event */
if (host->ops->card_event)
host->ops->card_event(host);
+ present = sdhci_get_cd(mmc);
spin_lock_irqsave(&host->lock, flags);
- /* Check host->mrq first in case we are runtime suspended */
- if (host->mrq && !sdhci_do_get_cd(host)) {
+ if (host->mrq && !present) {
pr_err("%s: Card removed during transfer!\n",
mmc_hostname(host->mmc));
pr_err("%s: Resetting controller.\n",
--
1.9.1.423.g4596e3a
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