From 1af36b2a993dddfa3d6860ec4879c9e8abc9b976 Mon Sep 17 00:00:00 2001 From: Lauri Hintsala Date: Tue, 17 Jul 2012 17:16:09 +0300 Subject: [PATCH] mmc: mxs-mmc: fix deadlock in SDIO IRQ case 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: [] mxs_mmc_enable_sdio_irq+0x18/0xd4 [ 79.660000] [ 79.660000] but task is already holding lock: [ 79.660000] (&(&host->lock)->rlock#2){-.....}, at: [] 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: [] mxs_mmc_irq_handler+0x1c/0xe8 [ 79.660000] [ 79.660000] stack backtrace: [ 79.660000] [] (unwind_backtrace+0x0/0xf4) from [] (__lock_acquire+0x1948/0x1d48) [ 79.660000] [] (__lock_acquire+0x1948/0x1d48) from [] (lock_acquire+0xe0/0xf8) [ 79.660000] [] (lock_acquire+0xe0/0xf8) from [] (_raw_spin_lock_irqsave+0x44/0x58) [ 79.660000] [] (_raw_spin_lock_irqsave+0x44/0x58) from [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) [ 79.660000] [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [] (mxs_mmc_irq_handler+0xd4/0xe8) [ 79.660000] [] (mxs_mmc_irq_handler+0xd4/0xe8) from [] (handle_irq_event_percpu+0x70/0x254) [ 79.660000] [] (handle_irq_event_percpu+0x70/0x254) from [] (handle_irq_event+0x3c/0x5c) [ 79.660000] [] (handle_irq_event+0x3c/0x5c) from [] (handle_level_irq+0x90/0x110) [ 79.660000] [] (handle_level_irq+0x90/0x110) from [] (generic_handle_irq+0x38/0x50) [ 79.660000] [] (generic_handle_irq+0x38/0x50) from [] (handle_IRQ+0x30/0x84) [ 79.660000] [] (handle_IRQ+0x30/0x84) from [] (__irq_svc+0x38/0x60) [ 79.660000] [] (__irq_svc+0x38/0x60) from [] (default_idle+0x2c/0x40) [ 79.660000] [] (default_idle+0x2c/0x40) from [] (cpu_idle+0x64/0xcc) [ 79.660000] [] (cpu_idle+0x64/0xcc) from [] (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] [] (unwind_backtrace+0x0/0xf4) from [] (do_raw_spin_lock+0xf0/0x144) [ 79.660000] [] (do_raw_spin_lock+0xf0/0x144) from [] (_raw_spin_lock_irqsave+0x4c/0x58) [ 79.660000] [] (_raw_spin_lock_irqsave+0x4c/0x58) from [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) [ 79.660000] [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [] (mxs_mmc_irq_handler+0xd4/0xe8) [ 79.660000] [] (mxs_mmc_irq_handler+0xd4/0xe8) from [] (handle_irq_event_percpu+0x70/0x254) [ 79.660000] [] (handle_irq_event_percpu+0x70/0x254) from [] (handle_irq_event+0x3c/0x5c) [ 79.660000] [] (handle_irq_event+0x3c/0x5c) from [] (handle_level_irq+0x90/0x110) [ 79.660000] [] (handle_level_irq+0x90/0x110) from [] (generic_handle_irq+0x38/0x50) [ 79.660000] [] (generic_handle_irq+0x38/0x50) from [] (handle_IRQ+0x30/0x84) [ 79.660000] [] (handle_IRQ+0x30/0x84) from [] (__irq_svc+0x38/0x60) [ 79.660000] [] (__irq_svc+0x38/0x60) from [] (default_idle+0x2c/0x40) [ 79.660000] [] (default_idle+0x2c/0x40) from [] (cpu_idle+0x64/0xcc) [ 79.660000] [] (cpu_idle+0x64/0xcc) from [] (start_kernel+0x244/0x2c8) Signed-off-by: Lauri Hintsala Acked-by: Shawn Guo Cc: stable Signed-off-by: Chris Ball --- drivers/mmc/host/mxs-mmc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c index a51f9309ffb..e62e58e5053 100644 --- a/drivers/mmc/host/mxs-mmc.c +++ b/drivers/mmc/host/mxs-mmc.c @@ -285,11 +285,11 @@ static irqreturn_t mxs_mmc_irq_handler(int irq, void *dev_id) writel(stat & MXS_MMC_IRQ_BITS, host->base + HW_SSP_CTRL1(host) + STMP_OFFSET_REG_CLR); + 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) -- 2.20.1