[3.13.y-ckt stable] Patch "mmc: sdhci: Fix sleep in atomic after inserting SD card" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Thu Feb 19 00:28:51 UTC 2015
This is a note to let you know that I have just added a patch titled
mmc: sdhci: Fix sleep in atomic after inserting SD card
to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue
This patch is scheduled to be released in version 3.13.11-ckt16.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From b550eee7f7b4ba09de413cb357ef9abc19f4aaa0 Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Date: Mon, 5 Jan 2015 10:50:15 +0100
Subject: mmc: sdhci: Fix sleep in atomic after inserting SD card
commit 2836766a9d0bd02c66073f8dd44796e6cc23848d upstream.
Sleep in atomic context happened on Trats2 board after inserting or
removing SD card because mmc_gpio_get_cd() was called under spin lock.
Fix this by moving card detection earlier, before acquiring spin lock.
The mmc_gpio_get_cd() call does not have to be protected by spin lock
because it does not access any sdhci internal data.
The sdhci_do_get_cd() call access host flags (SDHCI_DEVICE_DEAD). After
moving it out side of spin lock it could theoretically race with driver
removal but still there is no actual protection against manual card
eject.
Dmesg after inserting SD card:
[ 41.663414] BUG: sleeping function called from invalid context at drivers/gpio/gpiolib.c:1511
[ 41.670469] in_atomic(): 1, irqs_disabled(): 128, pid: 30, name: kworker/u8:1
[ 41.677580] INFO: lockdep is turned off.
[ 41.681486] irq event stamp: 61972
[ 41.684872] hardirqs last enabled at (61971): [<c0490ee0>] _raw_spin_unlock_irq+0x24/0x5c
[ 41.693118] hardirqs last disabled at (61972): [<c04907ac>] _raw_spin_lock_irq+0x18/0x54
[ 41.701190] softirqs last enabled at (61648): [<c0026fd4>] __do_softirq+0x234/0x2c8
[ 41.708914] softirqs last disabled at (61631): [<c00273a0>] irq_exit+0xd0/0x114
[ 41.716206] Preemption disabled at:[< (null)>] (null)
[ 41.721500]
[ 41.722985] CPU: 3 PID: 30 Comm: kworker/u8:1 Tainted: G W 3.18.0-rc5-next-20141121 #883
[ 41.732111] Workqueue: kmmcd mmc_rescan
[ 41.735945] [<c0014d2c>] (unwind_backtrace) from [<c0011c80>] (show_stack+0x10/0x14)
[ 41.743661] [<c0011c80>] (show_stack) from [<c0489d14>] (dump_stack+0x70/0xbc)
[ 41.750867] [<c0489d14>] (dump_stack) from [<c0228b74>] (gpiod_get_raw_value_cansleep+0x18/0x30)
[ 41.759628] [<c0228b74>] (gpiod_get_raw_value_cansleep) from [<c03646e8>] (mmc_gpio_get_cd+0x38/0x58)
[ 41.768821] [<c03646e8>] (mmc_gpio_get_cd) from [<c036d378>] (sdhci_request+0x50/0x1a4)
[ 41.776808] [<c036d378>] (sdhci_request) from [<c0357934>] (mmc_start_request+0x138/0x268)
[ 41.785051] [<c0357934>] (mmc_start_request) from [<c0357cc8>] (mmc_wait_for_req+0x58/0x1a0)
[ 41.793469] [<c0357cc8>] (mmc_wait_for_req) from [<c0357e68>] (mmc_wait_for_cmd+0x58/0x78)
[ 41.801714] [<c0357e68>] (mmc_wait_for_cmd) from [<c0361c00>] (mmc_io_rw_direct_host+0x98/0x124)
[ 41.810480] [<c0361c00>] (mmc_io_rw_direct_host) from [<c03620f8>] (sdio_reset+0x2c/0x64)
[ 41.818641] [<c03620f8>] (sdio_reset) from [<c035a3d8>] (mmc_rescan+0x254/0x2e4)
[ 41.826028] [<c035a3d8>] (mmc_rescan) from [<c003a0e0>] (process_one_work+0x180/0x3f4)
[ 41.833920] [<c003a0e0>] (process_one_work) from [<c003a3bc>] (worker_thread+0x34/0x4b0)
[ 41.841991] [<c003a3bc>] (worker_thread) from [<c003fed8>] (kthread+0xe4/0x104)
[ 41.849285] [<c003fed8>] (kthread) from [<c000f268>] (ret_from_fork+0x14/0x2c)
[ 42.038276] mmc0: new high speed SDHC card at address 1234
Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Fixes: 94144a465dd0 ("mmc: sdhci: add get_cd() implementation")
Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/mmc/host/sdhci.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 3c71920..dbc064b 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1333,6 +1333,8 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
sdhci_runtime_pm_get(host);
+ present = mmc_gpio_get_cd(host->mmc);
+
spin_lock_irqsave(&host->lock, flags);
WARN_ON(host->mrq != NULL);
@@ -1361,7 +1363,6 @@ 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)
@@ -2065,15 +2066,18 @@ 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_do_get_cd(host);
+
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
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