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authorLauri Hintsala <lauri.hintsala@bluegiga.com>2012-07-17 17:16:09 +0300
committerBen Hutchings <ben@decadent.org.uk>2012-09-19 15:04:39 +0100
commit2fa07abbe88fa0452121d13c44c95595b19ed67d (patch)
treeee0cd5bf72d53d5cddf5aadc8c43de87d6fc73b4
parent68b7b07e0d827a581058c5e4adb0a348e9a53a53 (diff)
mmc: mxs-mmc: fix deadlock in SDIO IRQ case
commit 1af36b2a993dddfa3d6860ec4879c9e8abc9b976 upstream. Release the lock before mmc_signal_sdio_irq is called by mxs_mmc_irq_handler. Backtrace: [ 79.660000] ============================================= [ 79.660000] [ INFO: possible recursive locking detected ] [ 79.660000] 3.4.0-00009-g3e96082-dirty #11 Not tainted [ 79.660000] --------------------------------------------- [ 79.660000] swapper/0 is trying to acquire lock: [ 79.660000] (&(&host->lock)->rlock#2){-.....}, at: [<c026ea3c>] mxs_mmc_enable_sdio_irq+0x18/0xd4 [ 79.660000] [ 79.660000] but task is already holding lock: [ 79.660000] (&(&host->lock)->rlock#2){-.....}, at: [<c026f744>] mxs_mmc_irq_handler+0x1c/0xe8 [ 79.660000] [ 79.660000] other info that might help us debug this: [ 79.660000] Possible unsafe locking scenario: [ 79.660000] [ 79.660000] CPU0 [ 79.660000] ---- [ 79.660000] lock(&(&host->lock)->rlock#2); [ 79.660000] lock(&(&host->lock)->rlock#2); [ 79.660000] [ 79.660000] *** DEADLOCK *** [ 79.660000] [ 79.660000] May be due to missing lock nesting notation [ 79.660000] [ 79.660000] 1 lock held by swapper/0: [ 79.660000] #0: (&(&host->lock)->rlock#2){-.....}, at: [<c026f744>] mxs_mmc_irq_handler+0x1c/0xe8 [ 79.660000] [ 79.660000] stack backtrace: [ 79.660000] [<c0014bd0>] (unwind_backtrace+0x0/0xf4) from [<c005f9c0>] (__lock_acquire+0x1948/0x1d48) [ 79.660000] [<c005f9c0>] (__lock_acquire+0x1948/0x1d48) from [<c005fea0>] (lock_acquire+0xe0/0xf8) [ 79.660000] [<c005fea0>] (lock_acquire+0xe0/0xf8) from [<c03a8460>] (_raw_spin_lock_irqsave+0x44/0x58) [ 79.660000] [<c03a8460>] (_raw_spin_lock_irqsave+0x44/0x58) from [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) [ 79.660000] [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) [ 79.660000] [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) from [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) [ 79.660000] [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) from [<c006bff8>] (handle_irq_event+0x3c/0x5c) [ 79.660000] [<c006bff8>] (handle_irq_event+0x3c/0x5c) from [<c006e6d0>] (handle_level_irq+0x90/0x110) [ 79.660000] [<c006e6d0>] (handle_level_irq+0x90/0x110) from [<c006b930>] (generic_handle_irq+0x38/0x50) [ 79.660000] [<c006b930>] (generic_handle_irq+0x38/0x50) from [<c00102fc>] (handle_IRQ+0x30/0x84) [ 79.660000] [<c00102fc>] (handle_IRQ+0x30/0x84) from [<c000f058>] (__irq_svc+0x38/0x60) [ 79.660000] [<c000f058>] (__irq_svc+0x38/0x60) from [<c0010520>] (default_idle+0x2c/0x40) [ 79.660000] [<c0010520>] (default_idle+0x2c/0x40) from [<c0010a90>] (cpu_idle+0x64/0xcc) [ 79.660000] [<c0010a90>] (cpu_idle+0x64/0xcc) from [<c04ff858>] (start_kernel+0x244/0x2c8) [ 79.660000] BUG: spinlock lockup on CPU#0, swapper/0 [ 79.660000] lock: c398cb2c, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0 [ 79.660000] [<c0014bd0>] (unwind_backtrace+0x0/0xf4) from [<c01ddb1c>] (do_raw_spin_lock+0xf0/0x144) [ 79.660000] [<c01ddb1c>] (do_raw_spin_lock+0xf0/0x144) from [<c03a8468>] (_raw_spin_lock_irqsave+0x4c/0x58) [ 79.660000] [<c03a8468>] (_raw_spin_lock_irqsave+0x4c/0x58) from [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) [ 79.660000] [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) [ 79.660000] [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) from [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) [ 79.660000] [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) from [<c006bff8>] (handle_irq_event+0x3c/0x5c) [ 79.660000] [<c006bff8>] (handle_irq_event+0x3c/0x5c) from [<c006e6d0>] (handle_level_irq+0x90/0x110) [ 79.660000] [<c006e6d0>] (handle_level_irq+0x90/0x110) from [<c006b930>] (generic_handle_irq+0x38/0x50) [ 79.660000] [<c006b930>] (generic_handle_irq+0x38/0x50) from [<c00102fc>] (handle_IRQ+0x30/0x84) [ 79.660000] [<c00102fc>] (handle_IRQ+0x30/0x84) from [<c000f058>] (__irq_svc+0x38/0x60) [ 79.660000] [<c000f058>] (__irq_svc+0x38/0x60) from [<c0010520>] (default_idle+0x2c/0x40) [ 79.660000] [<c0010520>] (default_idle+0x2c/0x40) from [<c0010a90>] (cpu_idle+0x64/0xcc) [ 79.660000] [<c0010a90>] (cpu_idle+0x64/0xcc) from [<c04ff858>] (start_kernel+0x244/0x2c8) Signed-off-by: Lauri Hintsala <lauri.hintsala@bluegiga.com> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/mmc/host/mxs-mmc.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
index 99b449d26a4d..5b79f9b59042 100644
--- a/drivers/mmc/host/mxs-mmc.c
+++ b/drivers/mmc/host/mxs-mmc.c
@@ -279,11 +279,11 @@ static irqreturn_t mxs_mmc_irq_handler(int irq, void *dev_id)
writel(stat & MXS_MMC_IRQ_BITS,
host->base + HW_SSP_CTRL1 + MXS_CLR_ADDR);
+ spin_unlock(&host->lock);
+
if ((stat & BM_SSP_CTRL1_SDIO_IRQ) && (stat & BM_SSP_CTRL1_SDIO_IRQ_EN))
mmc_signal_sdio_irq(host->mmc);
- spin_unlock(&host->lock);
-
if (stat & BM_SSP_CTRL1_RESP_TIMEOUT_IRQ)
cmd->error = -ETIMEDOUT;
else if (stat & BM_SSP_CTRL1_RESP_ERR_IRQ)