| Message ID | 4FFC367A.8020100@bluegiga.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Dear Lauri Hintsala, [...] > --- a/drivers/mmc/host/mxs-mmc.c > +++ b/drivers/mmc/host/mxs-mmc.c > @@ -278,11 +278,11 @@ 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); > - Spinlock in irq handler is interesting too ;-) > if (stat & BM_SSP_CTRL1_RESP_TIMEOUT_IRQ) > cmd->error = -ETIMEDOUT; > else if (stat & BM_SSP_CTRL1_RESP_ERR_IRQ) > > > Is there any reason to keep mmc_signal_sdio_irq inside the spinlock? > mmc_signal_sdio_irq calls mxs_mmc_enable_sdio_irq and it tries to > acquire lock while it is already acquired. > > > Best regards, > Lauri Hintsala Best regards, Marek Vasut
On Tue, Jul 10, 2012 at 05:04:42PM +0300, Lauri Hintsala wrote: > Hi, > > I was able to get deadlock with CONFIG_DEBUG_SPINLOCK enabled. I > added also CONFIG_PROVE_LOCKING to get more verbose output. I got > following error message after SDIO device has been powered. > > I'm able to replicate issue with Linux next-20120710. Platform is imx28. > The bug is there probably because the driver hasn't been widely tested on SDIO card. > I found a way to fix this issue: > > --- a/drivers/mmc/host/mxs-mmc.c > +++ b/drivers/mmc/host/mxs-mmc.c > @@ -278,11 +278,11 @@ 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) > > > Is there any reason to keep mmc_signal_sdio_irq inside the spinlock? > mmc_signal_sdio_irq calls mxs_mmc_enable_sdio_irq and it tries to > acquire lock while it is already acquired. > The fix looks right to me. You can have my ack when you send a patch for it. Acked-by: Shawn Guo <shawn.guo@linaro.org>
On 07/11/2012 09:06 AM, Shawn Guo wrote: >> --- a/drivers/mmc/host/mxs-mmc.c >> +++ b/drivers/mmc/host/mxs-mmc.c >> @@ -278,11 +278,11 @@ 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) >> >> >> Is there any reason to keep mmc_signal_sdio_irq inside the spinlock? >> mmc_signal_sdio_irq calls mxs_mmc_enable_sdio_irq and it tries to >> acquire lock while it is already acquired. >> > The fix looks right to me. You can have my ack when you send a patch > for it. > > Acked-by: Shawn Guo <shawn.guo@linaro.org> OK, I'll send a patch. Thanks! Lauri
On Tue, Jul 10, 2012 at 05:02:52PM +0200, Marek Vasut wrote: > Dear Lauri Hintsala, > > [...] > > > --- a/drivers/mmc/host/mxs-mmc.c > > +++ b/drivers/mmc/host/mxs-mmc.c > > @@ -278,11 +278,11 @@ 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); > > - > > Spinlock in irq handler is interesting too ;-) > For you information, the following is what I learnt from Arnd when I was a beginner. Regards, Shawn --- Quote Begins --- A short form of the strict rules (there are better documentations out there) is: * If all users are outside of interrupt or tasklet context, use a bare spin_lock(). * If one user is in a tasklet context, use spin_lock() inside the tasklet, but spin_lock_bh() outside, to prevent the tasklet from interrupting the critical section. Code that can be called in either tasklet or regular context needs to use spin_lock_bh() as well. * If one user is in interrupt context, use spin_lock() inside of the interrupt handler, but spin_lock_irq() in tasklet and normal context (not spin_lock_irqsave()), to prevent the interrupt from happening during the critical section. * Use spin_lock_irqsave() only for functions that can be called in either interrupt or non-interrupt context. Most drivers don't need this at all. The simplified rule would be to always use spin_lock_irqsave(), because that does not require you to understand what you are doing. My position is that it is better to use the stricter rules, because that documents that you actually do understand what you are doing ;-) It's also slightly more efficient, because it avoids having to save the interrupt status in a variable. --- Quote Ends ---
On Wed, 11 Jul 2012 14:06:09 +0800 Shawn Guo <shawn.guo@linaro.org> wrote: > > I found a way to fix this issue: > > > > --- a/drivers/mmc/host/mxs-mmc.c > > +++ b/drivers/mmc/host/mxs-mmc.c > > @@ -278,11 +278,11 @@ 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) > > > > > > Is there any reason to keep mmc_signal_sdio_irq inside the spinlock? > > mmc_signal_sdio_irq calls mxs_mmc_enable_sdio_irq and it tries to > > acquire lock while it is already acquired. > > > The fix looks right to me. You can have my ack when you send a patch > for it. > > Acked-by: Shawn Guo <shawn.guo@linaro.org> I ran into the same problem today, but the proposed fix doesn't seem to work for me: ---schnipp--- # modprobe libertas_sdio [ 59.200000] lib80211: common routines for IEEE802.11 drivers [ 59.240000] cfg80211: Calling CRDA to update world regulatory domain [ 59.320000] libertas_sdio: Libertas SDIO driver [ 59.330000] libertas_sdio: Copyright Pierre Ossman # modprobe mxs-mmc [ 64.210000] mxs-mmc 80010000.ssp: initialized [ 64.260000] mxs-mmc 80034000.ssp: initialized [ 64.270000] mmc0: new SDIO card at address 0001 # [ 65.440000] libertas_sdio mmc0:0001:1: (unregistered net_device): 00:13:04:80:00:3f, fw 9.70.3p24, cap 0x00000303 [ 65.470000] [ 65.470000] ============================================= [ 65.470000] [ INFO: possible recursive locking detected ] [ 65.470000] 3.5.0-rc5 #2 Not tainted [ 65.470000] --------------------------------------------- [ 65.470000] ksdioirqd/mmc0/73 is trying to acquire lock: [ 65.470000] (&(&host->lock)->rlock#2){-.-...}, at: [<bf054120>] mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc] [ 65.470000] [ 65.470000] but task is already holding lock: [ 65.470000] (&(&host->lock)->rlock#2){-.-...}, at: [<bf054120>] mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc] [ 65.470000] [ 65.470000] other info that might help us debug this: [ 65.470000] Possible unsafe locking scenario: [ 65.470000] [ 65.470000] CPU0 [ 65.470000] ---- [ 65.470000] lock(&(&host->lock)->rlock#2); [ 65.470000] lock(&(&host->lock)->rlock#2); [ 65.470000] [ 65.470000] *** DEADLOCK *** [ 65.470000] [ 65.470000] May be due to missing lock nesting notation [ 65.470000] [ 65.470000] 1 lock held by ksdioirqd/mmc0/73: [ 65.470000] #0: (&(&host->lock)->rlock#2){-.-...}, at: [<bf054120>] mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc] [ 65.470000] [ 65.470000] stack backtrace: [ 65.470000] [<c0014990>] (unwind_backtrace+0x0/0xf4) from [<c005ccb8>] (__lock_acquire+0x14f8/0x1b98) [ 65.470000] [<c005ccb8>] (__lock_acquire+0x14f8/0x1b98) from [<c005d3f8>] (lock_acquire+0xa0/0x108) [ 65.470000] [<c005d3f8>] (lock_acquire+0xa0/0x108) from [<c02f671c>] (_raw_spin_lock_irqsave+0x48/0x5c) [ 65.470000] [<c02f671c>] (_raw_spin_lock_irqsave+0x48/0x5c) from [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) [ 65.470000] [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) from [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) [ 65.470000] [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) from [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) [ 65.470000] [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) from [<c003c324>] (kthread+0x8c/0x98) [ 65.470000] [<c003c324>] (kthread+0x8c/0x98) from [<c00101ac>] (kernel_thread_exit+0x0/0x8) [ 65.470000] BUG: spinlock lockup suspected on CPU#0, ksdioirqd/mmc0/73 [ 65.470000] lock: 0xc3358724, .magic: dead4ead, .owner: ksdioirqd/mmc0/73, .owner_cpu: 0 [ 65.470000] [<c0014990>] (unwind_backtrace+0x0/0xf4) from [<c01b46b0>] (do_raw_spin_lock+0x100/0x144) [ 65.470000] [<c01b46b0>] (do_raw_spin_lock+0x100/0x144) from [<c02f6724>] (_raw_spin_lock_irqsave+0x50/0x5c) [ 65.470000] [<c02f6724>] (_raw_spin_lock_irqsave+0x50/0x5c) from [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) [ 65.470000] [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) from [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) [ 65.470000] [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) from [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) [ 65.470000] [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) from [<c003c324>] (kthread+0x8c/0x98) [ 65.470000] [<c003c324>] (kthread+0x8c/0x98) from [<c00101ac>] (kernel_thread_exit+0x0/0x8) ---schnapp--- Any hints how to work around or fix this, would be appreciated Attila Kinali
On Thu, Jul 12, 2012 at 04:00:08PM +0200, Attila Kinali wrote: > On Wed, 11 Jul 2012 14:06:09 +0800 > Shawn Guo <shawn.guo@linaro.org> wrote: > > > > > I found a way to fix this issue: > > > > > > --- a/drivers/mmc/host/mxs-mmc.c > > > +++ b/drivers/mmc/host/mxs-mmc.c > > > @@ -278,11 +278,11 @@ 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) > > > > > > > > > Is there any reason to keep mmc_signal_sdio_irq inside the spinlock? > > > mmc_signal_sdio_irq calls mxs_mmc_enable_sdio_irq and it tries to > > > acquire lock while it is already acquired. > > > > > The fix looks right to me. You can have my ack when you send a patch > > for it. > > > > Acked-by: Shawn Guo <shawn.guo@linaro.org> > > I ran into the same problem today, but the proposed fix doesn't seem > to work for me: > It's a different problem from what Lauri reported and fixed. I haven't played SDIO card that much, so I'm not completely clear about the SDIO calling sequence, but is it reasonable that mxs_mmc_enable_sdio_irq is being called recursively? Regards, Shawn > ---schnipp--- > # modprobe libertas_sdio > [ 59.200000] lib80211: common routines for IEEE802.11 drivers > [ 59.240000] cfg80211: Calling CRDA to update world regulatory domain > [ 59.320000] libertas_sdio: Libertas SDIO driver > [ 59.330000] libertas_sdio: Copyright Pierre Ossman > # modprobe mxs-mmc > [ 64.210000] mxs-mmc 80010000.ssp: initialized > [ 64.260000] mxs-mmc 80034000.ssp: initialized > [ 64.270000] mmc0: new SDIO card at address 0001 > # [ 65.440000] libertas_sdio mmc0:0001:1: (unregistered net_device): 00:13:04:80:00:3f, fw 9.70.3p24, cap 0x00000303 > [ 65.470000] > [ 65.470000] ============================================= > [ 65.470000] [ INFO: possible recursive locking detected ] > [ 65.470000] 3.5.0-rc5 #2 Not tainted > [ 65.470000] --------------------------------------------- > [ 65.470000] ksdioirqd/mmc0/73 is trying to acquire lock: > [ 65.470000] (&(&host->lock)->rlock#2){-.-...}, at: [<bf054120>] mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc] > [ 65.470000] > [ 65.470000] but task is already holding lock: > [ 65.470000] (&(&host->lock)->rlock#2){-.-...}, at: [<bf054120>] mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc] > [ 65.470000] > [ 65.470000] other info that might help us debug this: > [ 65.470000] Possible unsafe locking scenario: > [ 65.470000] > [ 65.470000] CPU0 > [ 65.470000] ---- > [ 65.470000] lock(&(&host->lock)->rlock#2); > [ 65.470000] lock(&(&host->lock)->rlock#2); > [ 65.470000] > [ 65.470000] *** DEADLOCK *** > [ 65.470000] > [ 65.470000] May be due to missing lock nesting notation > [ 65.470000] > [ 65.470000] 1 lock held by ksdioirqd/mmc0/73: > [ 65.470000] #0: (&(&host->lock)->rlock#2){-.-...}, at: [<bf054120>] mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc] > [ 65.470000] > [ 65.470000] stack backtrace: > [ 65.470000] [<c0014990>] (unwind_backtrace+0x0/0xf4) from [<c005ccb8>] (__lock_acquire+0x14f8/0x1b98) > [ 65.470000] [<c005ccb8>] (__lock_acquire+0x14f8/0x1b98) from [<c005d3f8>] (lock_acquire+0xa0/0x108) > [ 65.470000] [<c005d3f8>] (lock_acquire+0xa0/0x108) from [<c02f671c>] (_raw_spin_lock_irqsave+0x48/0x5c) > [ 65.470000] [<c02f671c>] (_raw_spin_lock_irqsave+0x48/0x5c) from [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) > [ 65.470000] [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) from [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) > [ 65.470000] [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) from [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) > [ 65.470000] [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) from [<c003c324>] (kthread+0x8c/0x98) > [ 65.470000] [<c003c324>] (kthread+0x8c/0x98) from [<c00101ac>] (kernel_thread_exit+0x0/0x8) > [ 65.470000] BUG: spinlock lockup suspected on CPU#0, ksdioirqd/mmc0/73 > [ 65.470000] lock: 0xc3358724, .magic: dead4ead, .owner: ksdioirqd/mmc0/73, .owner_cpu: 0 > [ 65.470000] [<c0014990>] (unwind_backtrace+0x0/0xf4) from [<c01b46b0>] (do_raw_spin_lock+0x100/0x144) > [ 65.470000] [<c01b46b0>] (do_raw_spin_lock+0x100/0x144) from [<c02f6724>] (_raw_spin_lock_irqsave+0x50/0x5c) > [ 65.470000] [<c02f6724>] (_raw_spin_lock_irqsave+0x50/0x5c) from [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) > [ 65.470000] [<bf054120>] (mxs_mmc_enable_sdio_irq+0x18/0xdc [mxs_mmc]) from [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) > [ 65.470000] [<bf0541d0>] (mxs_mmc_enable_sdio_irq+0xc8/0xdc [mxs_mmc]) from [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) > [ 65.470000] [<c0219b38>] (sdio_irq_thread+0x1bc/0x274) from [<c003c324>] (kthread+0x8c/0x98) > [ 65.470000] [<c003c324>] (kthread+0x8c/0x98) from [<c00101ac>] (kernel_thread_exit+0x0/0x8) > ---schnapp--- > > Any hints how to work around or fix this, would be appreciated > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson
On Thu, 12 Jul 2012 22:39:53 +0800 Shawn Guo <shawn.guo@linaro.org> wrote: > > > > I ran into the same problem today, but the proposed fix doesn't seem > > to work for me: > > > It's a different problem from what Lauri reported and fixed. Ok... > I haven't > played SDIO card that much, so I'm not completely clear about the SDIO > calling sequence, but is it reasonable that mxs_mmc_enable_sdio_irq is > being called recursively? I don't know. I dont know the code at all and not how the sdio system works. But a quick check shows, that mxs_mmc_enable_sdio_irq does not call any other function (besides readel, writel) and hence cannot call itself. For me it rather looks like that there seem to be two consequtive irqs that get passed to sdio_irq_thread which then calls mxs_mmc_enable_sdio_irq. But with my limited knowledge i cannot check this theory. Can anyone give me some hints how i could verify this? Attila Kinali
--- a/drivers/mmc/host/mxs-mmc.c +++ b/drivers/mmc/host/mxs-mmc.c @@ -278,11 +278,11 @@ 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;
Hi, I was able to get deadlock with CONFIG_DEBUG_SPINLOCK enabled. I added also CONFIG_PROVE_LOCKING to get more verbose output. I got following error message after SDIO device has been powered. I'm able to replicate issue with Linux next-20120710. Platform is imx28. [ 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) I found a way to fix this issue: else if (stat & BM_SSP_CTRL1_RESP_ERR_IRQ) Is there any reason to keep mmc_signal_sdio_irq inside the spinlock? mmc_signal_sdio_irq calls mxs_mmc_enable_sdio_irq and it tries to acquire lock while it is already acquired. Best regards, Lauri Hintsala