| Message ID | 1477607684-5314-1-git-send-email-hotran@apm.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
Hi All, On Thu, Oct 27, 2016 at 3:34 PM, Hoan Tran <hotran@apm.com> wrote: > This patch fixes the lockdep warning below > > [ 7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) > [ 7.229776] ------------[ cut here ]------------ > [ 7.229787] WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 loc > kdep_trace_alloc+0xe0/0xf0 > [ 7.229790] Modules linked in: > [ 7.229793] > [ 7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 > ... > [ 7.229900] Call trace: > [ 7.229903] Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) > [ 7.229906] 7880: ffff8007da834000 0001000000000000 > [ 7.229909] 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d > [ 7.229912] 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f > [ 7.229915] 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 > [ 7.229918] 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 > [ 7.229921] 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 > [ 7.229923] 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 > [ 7.229926] 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 > [ 7.229929] 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 > [ 7.229932] 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f > [ 7.229936] [<ffff0000081111a0>] lockdep_trace_alloc+0xe0/0xf0 > [ 7.229940] [<ffff0000081f4950>] __kmalloc_track_caller+0x50/0x250 > [ 7.229945] [<ffff00000857c088>] devres_alloc_node+0x28/0x60 > [ 7.229949] [<ffff0000081220e0>] devm_request_threaded_irq+0x50/0xe0 > [ 7.229955] [<ffff0000087e6220>] pcc_mbox_request_channel+0x110/0x170 > [ 7.229960] [<ffff0000084b2660>] acpi_cppc_processor_probe+0x264/0x414 > [ 7.229963] [<ffff0000084ae9f4>] __acpi_processor_start+0x28/0xa0 > [ 7.229966] [<ffff0000084aeab0>] acpi_processor_start+0x44/0x54 > [ 7.229970] [<ffff00000857897c>] driver_probe_device+0x1fc/0x2b0 > [ 7.229974] [<ffff000008578ae4>] __driver_attach+0xb4/0xc0 > [ 7.229977] [<ffff00000857683c>] bus_for_each_dev+0x5c/0xa0 > [ 7.229980] [<ffff000008578110>] driver_attach+0x20/0x30 > [ 7.229983] [<ffff000008577c20>] bus_add_driver+0x110/0x230 > [ 7.229987] [<ffff000008579320>] driver_register+0x60/0x100 > [ 7.229991] [<ffff000008d478b8>] acpi_processor_driver_init+0x2c/0xb0 > [ 7.229996] [<ffff000008083168>] do_one_initcall+0x38/0x130 > [ 7.230000] [<ffff000008d20d6c>] kernel_init_freeable+0x210/0x2b4 > [ 7.230004] [<ffff000008945d90>] kernel_init+0x10/0x110 > [ 7.230007] [<ffff000008082e80>] ret_from_fork+0x10/0x50 > > It's because the spinlock inside pcc_mbox_request_channel() is > kept too long. This patch releases spinlock before request_irq() > and free_irq() to fix this issue as spinlock is only needed to > protect the channel data. > > Signed-off-by: Hoan Tran <hotran@apm.com> > --- > v3 > * Free mailbox irq before reset the channel data > * Free channel if it fails to request the mailbox irq > > v2 > * Release spinlock before request_irq() and free_irq() instead of > using mutex > > > drivers/mailbox/pcc.c | 70 +++++++++++++++++++++++++-------------------------- > 1 file changed, 35 insertions(+), 35 deletions(-) > > diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c > index 08c87fa..4b2f061 100644 > --- a/drivers/mailbox/pcc.c > +++ b/drivers/mailbox/pcc.c > @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) > } > > /** > + * pcc_mbox_free_channel - Clients call this to free their Channel. > + * > + * @chan: Pointer to the mailbox channel as returned by > + * pcc_mbox_request_channel() > + */ > +void pcc_mbox_free_channel(struct mbox_chan *chan) > +{ > + u32 id = chan - pcc_mbox_channels; > + unsigned long flags; > + > + if (!chan || !chan->cl) > + return; > + > + if (id >= pcc_mbox_ctrl.num_chans) { > + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); > + return; > + } > + > + if (pcc_doorbell_irq[id] > 0) > + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); > + > + spin_lock_irqsave(&chan->lock, flags); > + chan->cl = NULL; > + chan->active_req = NULL; > + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) > + chan->txdone_method = TXDONE_BY_POLL; > + > + spin_unlock_irqrestore(&chan->lock, flags); > +} > +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); > + > +/** > * pcc_mbox_request_channel - PCC clients call this function to > * request a pointer to their PCC subspace, from which they > * can get the details of communicating with the remote. > @@ -267,6 +299,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, > if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) > chan->txdone_method |= TXDONE_BY_ACK; > > + spin_unlock_irqrestore(&chan->lock, flags); > + > if (pcc_doorbell_irq[subspace_id] > 0) { > int rc; > > @@ -275,50 +309,16 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, > if (unlikely(rc)) { > dev_err(dev, "failed to register PCC interrupt %d\n", > pcc_doorbell_irq[subspace_id]); > + pcc_mbox_free_channel(chan); > chan = ERR_PTR(rc); > } > } > > - spin_unlock_irqrestore(&chan->lock, flags); > - > return chan; > } > EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); > > /** > - * pcc_mbox_free_channel - Clients call this to free their Channel. > - * > - * @chan: Pointer to the mailbox channel as returned by > - * pcc_mbox_request_channel() > - */ > -void pcc_mbox_free_channel(struct mbox_chan *chan) > -{ > - u32 id = chan - pcc_mbox_channels; > - unsigned long flags; > - > - if (!chan || !chan->cl) > - return; > - > - if (id >= pcc_mbox_ctrl.num_chans) { > - pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); > - return; > - } > - > - spin_lock_irqsave(&chan->lock, flags); > - chan->cl = NULL; > - chan->active_req = NULL; > - if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) > - chan->txdone_method = TXDONE_BY_POLL; > - > - if (pcc_doorbell_irq[id] > 0) > - devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); > - > - spin_unlock_irqrestore(&chan->lock, flags); > -} > -EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); > - > - > -/** > * pcc_send_data - Called from Mailbox Controller code. Used > * here only to ring the channel doorbell. The PCC client > * specific read/write is done in the client driver in > -- > 1.9.1 > Do you have any comments about this patch ? Thanks Hoan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
HI Hoan, On 11/9/2016 11:39 PM, Hoan Tran wrote: > Hi All, > > On Thu, Oct 27, 2016 at 3:34 PM, Hoan Tran <hotran@apm.com> wrote: >> This patch fixes the lockdep warning below >> >> [ 7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) >> [ 7.229776] ------------[ cut here ]------------ >> [ 7.229787] WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 loc >> kdep_trace_alloc+0xe0/0xf0 >> [ 7.229790] Modules linked in: >> [ 7.229793] >> [ 7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 >> ... >> [ 7.229900] Call trace: >> [ 7.229903] Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) >> [ 7.229906] 7880: ffff8007da834000 0001000000000000 >> [ 7.229909] 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d >> [ 7.229912] 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f >> [ 7.229915] 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 >> [ 7.229918] 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 >> [ 7.229921] 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 >> [ 7.229923] 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 >> [ 7.229926] 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 >> [ 7.229929] 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 >> [ 7.229932] 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f >> [ 7.229936] [<ffff0000081111a0>] lockdep_trace_alloc+0xe0/0xf0 >> [ 7.229940] [<ffff0000081f4950>] __kmalloc_track_caller+0x50/0x250 >> [ 7.229945] [<ffff00000857c088>] devres_alloc_node+0x28/0x60 >> [ 7.229949] [<ffff0000081220e0>] devm_request_threaded_irq+0x50/0xe0 >> [ 7.229955] [<ffff0000087e6220>] pcc_mbox_request_channel+0x110/0x170 >> [ 7.229960] [<ffff0000084b2660>] acpi_cppc_processor_probe+0x264/0x414 >> [ 7.229963] [<ffff0000084ae9f4>] __acpi_processor_start+0x28/0xa0 >> [ 7.229966] [<ffff0000084aeab0>] acpi_processor_start+0x44/0x54 >> [ 7.229970] [<ffff00000857897c>] driver_probe_device+0x1fc/0x2b0 >> [ 7.229974] [<ffff000008578ae4>] __driver_attach+0xb4/0xc0 >> [ 7.229977] [<ffff00000857683c>] bus_for_each_dev+0x5c/0xa0 >> [ 7.229980] [<ffff000008578110>] driver_attach+0x20/0x30 >> [ 7.229983] [<ffff000008577c20>] bus_add_driver+0x110/0x230 >> [ 7.229987] [<ffff000008579320>] driver_register+0x60/0x100 >> [ 7.229991] [<ffff000008d478b8>] acpi_processor_driver_init+0x2c/0xb0 >> [ 7.229996] [<ffff000008083168>] do_one_initcall+0x38/0x130 >> [ 7.230000] [<ffff000008d20d6c>] kernel_init_freeable+0x210/0x2b4 >> [ 7.230004] [<ffff000008945d90>] kernel_init+0x10/0x110 >> [ 7.230007] [<ffff000008082e80>] ret_from_fork+0x10/0x50 >> >> It's because the spinlock inside pcc_mbox_request_channel() is >> kept too long. This patch releases spinlock before request_irq() >> and free_irq() to fix this issue as spinlock is only needed to >> protect the channel data. >> >> Signed-off-by: Hoan Tran <hotran@apm.com> >> --- >> v3 >> * Free mailbox irq before reset the channel data >> * Free channel if it fails to request the mailbox irq >> >> v2 >> * Release spinlock before request_irq() and free_irq() instead of >> using mutex >> >> >> drivers/mailbox/pcc.c | 70 +++++++++++++++++++++++++-------------------------- >> 1 file changed, 35 insertions(+), 35 deletions(-) >> >> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c >> index 08c87fa..4b2f061 100644 >> --- a/drivers/mailbox/pcc.c >> +++ b/drivers/mailbox/pcc.c >> @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) >> } >> >> /** >> + * pcc_mbox_free_channel - Clients call this to free their Channel. >> + * >> + * @chan: Pointer to the mailbox channel as returned by >> + * pcc_mbox_request_channel() >> + */ >> +void pcc_mbox_free_channel(struct mbox_chan *chan) >> +{ >> + u32 id = chan - pcc_mbox_channels; >> + unsigned long flags; >> + >> + if (!chan || !chan->cl) >> + return; >> + >> + if (id >= pcc_mbox_ctrl.num_chans) { >> + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); >> + return; >> + } >> + >> + if (pcc_doorbell_irq[id] > 0) >> + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); >> + >> + spin_lock_irqsave(&chan->lock, flags); >> + chan->cl = NULL; >> + chan->active_req = NULL; >> + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) >> + chan->txdone_method = TXDONE_BY_POLL; >> + >> + spin_unlock_irqrestore(&chan->lock, flags); >> +} >> +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); >> + >> +/** >> * pcc_mbox_request_channel - PCC clients call this function to >> * request a pointer to their PCC subspace, from which they >> * can get the details of communicating with the remote. >> @@ -267,6 +299,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, >> if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) >> chan->txdone_method |= TXDONE_BY_ACK; >> >> + spin_unlock_irqrestore(&chan->lock, flags); >> + >> if (pcc_doorbell_irq[subspace_id] > 0) { >> int rc; >> >> @@ -275,50 +309,16 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, >> if (unlikely(rc)) { >> dev_err(dev, "failed to register PCC interrupt %d\n", >> pcc_doorbell_irq[subspace_id]); >> + pcc_mbox_free_channel(chan); >> chan = ERR_PTR(rc); >> } >> } >> >> - spin_unlock_irqrestore(&chan->lock, flags); >> - >> return chan; >> } >> EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); >> >> /** >> - * pcc_mbox_free_channel - Clients call this to free their Channel. >> - * >> - * @chan: Pointer to the mailbox channel as returned by >> - * pcc_mbox_request_channel() >> - */ >> -void pcc_mbox_free_channel(struct mbox_chan *chan) >> -{ >> - u32 id = chan - pcc_mbox_channels; >> - unsigned long flags; >> - >> - if (!chan || !chan->cl) >> - return; >> - >> - if (id >= pcc_mbox_ctrl.num_chans) { >> - pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); >> - return; >> - } >> - >> - spin_lock_irqsave(&chan->lock, flags); >> - chan->cl = NULL; >> - chan->active_req = NULL; >> - if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) >> - chan->txdone_method = TXDONE_BY_POLL; >> - >> - if (pcc_doorbell_irq[id] > 0) >> - devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); >> - >> - spin_unlock_irqrestore(&chan->lock, flags); >> -} >> -EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); Instead of completely relocating an exported function within the file, I think we can just include the "pcc.h" header, which makes it a little easier to review. Otherwise, the control flow looks ok now. -- Thanks, Prashanth -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On Sun, Nov 13, 2016 at 11:44 AM, Prakash, Prashanth <pprakash@codeaurora.org> wrote: > HI Hoan, > > On 11/9/2016 11:39 PM, Hoan Tran wrote: >> Hi All, >> >> On Thu, Oct 27, 2016 at 3:34 PM, Hoan Tran <hotran@apm.com> wrote: >>> This patch fixes the lockdep warning below >>> >>> [ 7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) >>> [ 7.229776] ------------[ cut here ]------------ >>> [ 7.229787] WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 loc >>> kdep_trace_alloc+0xe0/0xf0 >>> [ 7.229790] Modules linked in: >>> [ 7.229793] >>> [ 7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 >>> ... >>> [ 7.229900] Call trace: >>> [ 7.229903] Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) >>> [ 7.229906] 7880: ffff8007da834000 0001000000000000 >>> [ 7.229909] 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d >>> [ 7.229912] 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f >>> [ 7.229915] 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 >>> [ 7.229918] 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 >>> [ 7.229921] 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 >>> [ 7.229923] 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 >>> [ 7.229926] 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 >>> [ 7.229929] 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 >>> [ 7.229932] 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f >>> [ 7.229936] [<ffff0000081111a0>] lockdep_trace_alloc+0xe0/0xf0 >>> [ 7.229940] [<ffff0000081f4950>] __kmalloc_track_caller+0x50/0x250 >>> [ 7.229945] [<ffff00000857c088>] devres_alloc_node+0x28/0x60 >>> [ 7.229949] [<ffff0000081220e0>] devm_request_threaded_irq+0x50/0xe0 >>> [ 7.229955] [<ffff0000087e6220>] pcc_mbox_request_channel+0x110/0x170 >>> [ 7.229960] [<ffff0000084b2660>] acpi_cppc_processor_probe+0x264/0x414 >>> [ 7.229963] [<ffff0000084ae9f4>] __acpi_processor_start+0x28/0xa0 >>> [ 7.229966] [<ffff0000084aeab0>] acpi_processor_start+0x44/0x54 >>> [ 7.229970] [<ffff00000857897c>] driver_probe_device+0x1fc/0x2b0 >>> [ 7.229974] [<ffff000008578ae4>] __driver_attach+0xb4/0xc0 >>> [ 7.229977] [<ffff00000857683c>] bus_for_each_dev+0x5c/0xa0 >>> [ 7.229980] [<ffff000008578110>] driver_attach+0x20/0x30 >>> [ 7.229983] [<ffff000008577c20>] bus_add_driver+0x110/0x230 >>> [ 7.229987] [<ffff000008579320>] driver_register+0x60/0x100 >>> [ 7.229991] [<ffff000008d478b8>] acpi_processor_driver_init+0x2c/0xb0 >>> [ 7.229996] [<ffff000008083168>] do_one_initcall+0x38/0x130 >>> [ 7.230000] [<ffff000008d20d6c>] kernel_init_freeable+0x210/0x2b4 >>> [ 7.230004] [<ffff000008945d90>] kernel_init+0x10/0x110 >>> [ 7.230007] [<ffff000008082e80>] ret_from_fork+0x10/0x50 >>> >>> It's because the spinlock inside pcc_mbox_request_channel() is >>> kept too long. This patch releases spinlock before request_irq() >>> and free_irq() to fix this issue as spinlock is only needed to >>> protect the channel data. >>> >>> Signed-off-by: Hoan Tran <hotran@apm.com> >>> --- >>> v3 >>> * Free mailbox irq before reset the channel data >>> * Free channel if it fails to request the mailbox irq >>> >>> v2 >>> * Release spinlock before request_irq() and free_irq() instead of >>> using mutex >>> >>> >>> drivers/mailbox/pcc.c | 70 +++++++++++++++++++++++++-------------------------- >>> 1 file changed, 35 insertions(+), 35 deletions(-) >>> >>> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c >>> index 08c87fa..4b2f061 100644 >>> --- a/drivers/mailbox/pcc.c >>> +++ b/drivers/mailbox/pcc.c >>> @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) >>> } >>> >>> /** >>> + * pcc_mbox_free_channel - Clients call this to free their Channel. >>> + * >>> + * @chan: Pointer to the mailbox channel as returned by >>> + * pcc_mbox_request_channel() >>> + */ >>> +void pcc_mbox_free_channel(struct mbox_chan *chan) >>> +{ >>> + u32 id = chan - pcc_mbox_channels; >>> + unsigned long flags; >>> + >>> + if (!chan || !chan->cl) >>> + return; >>> + >>> + if (id >= pcc_mbox_ctrl.num_chans) { >>> + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); >>> + return; >>> + } >>> + >>> + if (pcc_doorbell_irq[id] > 0) >>> + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); >>> + >>> + spin_lock_irqsave(&chan->lock, flags); >>> + chan->cl = NULL; >>> + chan->active_req = NULL; >>> + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) >>> + chan->txdone_method = TXDONE_BY_POLL; >>> + >>> + spin_unlock_irqrestore(&chan->lock, flags); >>> +} >>> +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); >>> + >>> +/** >>> * pcc_mbox_request_channel - PCC clients call this function to >>> * request a pointer to their PCC subspace, from which they >>> * can get the details of communicating with the remote. >>> @@ -267,6 +299,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, >>> if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) >>> chan->txdone_method |= TXDONE_BY_ACK; >>> >>> + spin_unlock_irqrestore(&chan->lock, flags); >>> + >>> if (pcc_doorbell_irq[subspace_id] > 0) { >>> int rc; >>> >>> @@ -275,50 +309,16 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, >>> if (unlikely(rc)) { >>> dev_err(dev, "failed to register PCC interrupt %d\n", >>> pcc_doorbell_irq[subspace_id]); >>> + pcc_mbox_free_channel(chan); >>> chan = ERR_PTR(rc); >>> } >>> } >>> >>> - spin_unlock_irqrestore(&chan->lock, flags); >>> - >>> return chan; >>> } >>> EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); >>> >>> /** >>> - * pcc_mbox_free_channel - Clients call this to free their Channel. >>> - * >>> - * @chan: Pointer to the mailbox channel as returned by >>> - * pcc_mbox_request_channel() >>> - */ >>> -void pcc_mbox_free_channel(struct mbox_chan *chan) >>> -{ >>> - u32 id = chan - pcc_mbox_channels; >>> - unsigned long flags; >>> - >>> - if (!chan || !chan->cl) >>> - return; >>> - >>> - if (id >= pcc_mbox_ctrl.num_chans) { >>> - pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); >>> - return; >>> - } >>> - >>> - spin_lock_irqsave(&chan->lock, flags); >>> - chan->cl = NULL; >>> - chan->active_req = NULL; >>> - if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) >>> - chan->txdone_method = TXDONE_BY_POLL; >>> - >>> - if (pcc_doorbell_irq[id] > 0) >>> - devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); >>> - >>> - spin_unlock_irqrestore(&chan->lock, flags); >>> -} >>> -EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); > Instead of completely relocating an exported function within the file, I think > we can just include the "pcc.h" header, which makes it a little easier to review. I just sent out another patch which included pcc.h instead. Thanks Hoan > > Otherwise, the control flow looks ok now. > > -- > Thanks, > Prashanth -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c index 08c87fa..4b2f061 100644 --- a/drivers/mailbox/pcc.c +++ b/drivers/mailbox/pcc.c @@ -224,6 +224,38 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p) } /** + * pcc_mbox_free_channel - Clients call this to free their Channel. + * + * @chan: Pointer to the mailbox channel as returned by + * pcc_mbox_request_channel() + */ +void pcc_mbox_free_channel(struct mbox_chan *chan) +{ + u32 id = chan - pcc_mbox_channels; + unsigned long flags; + + if (!chan || !chan->cl) + return; + + if (id >= pcc_mbox_ctrl.num_chans) { + pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); + return; + } + + if (pcc_doorbell_irq[id] > 0) + devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); + + spin_lock_irqsave(&chan->lock, flags); + chan->cl = NULL; + chan->active_req = NULL; + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) + chan->txdone_method = TXDONE_BY_POLL; + + spin_unlock_irqrestore(&chan->lock, flags); +} +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); + +/** * pcc_mbox_request_channel - PCC clients call this function to * request a pointer to their PCC subspace, from which they * can get the details of communicating with the remote. @@ -267,6 +299,8 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) chan->txdone_method |= TXDONE_BY_ACK; + spin_unlock_irqrestore(&chan->lock, flags); + if (pcc_doorbell_irq[subspace_id] > 0) { int rc; @@ -275,50 +309,16 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, if (unlikely(rc)) { dev_err(dev, "failed to register PCC interrupt %d\n", pcc_doorbell_irq[subspace_id]); + pcc_mbox_free_channel(chan); chan = ERR_PTR(rc); } } - spin_unlock_irqrestore(&chan->lock, flags); - return chan; } EXPORT_SYMBOL_GPL(pcc_mbox_request_channel); /** - * pcc_mbox_free_channel - Clients call this to free their Channel. - * - * @chan: Pointer to the mailbox channel as returned by - * pcc_mbox_request_channel() - */ -void pcc_mbox_free_channel(struct mbox_chan *chan) -{ - u32 id = chan - pcc_mbox_channels; - unsigned long flags; - - if (!chan || !chan->cl) - return; - - if (id >= pcc_mbox_ctrl.num_chans) { - pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n"); - return; - } - - spin_lock_irqsave(&chan->lock, flags); - chan->cl = NULL; - chan->active_req = NULL; - if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) - chan->txdone_method = TXDONE_BY_POLL; - - if (pcc_doorbell_irq[id] > 0) - devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan); - - spin_unlock_irqrestore(&chan->lock, flags); -} -EXPORT_SYMBOL_GPL(pcc_mbox_free_channel); - - -/** * pcc_send_data - Called from Mailbox Controller code. Used * here only to ring the channel doorbell. The PCC client * specific read/write is done in the client driver in
This patch fixes the lockdep warning below [ 7.229767] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) [ 7.229776] ------------[ cut here ]------------ [ 7.229787] WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 loc kdep_trace_alloc+0xe0/0xf0 [ 7.229790] Modules linked in: [ 7.229793] [ 7.229798] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 ... [ 7.229900] Call trace: [ 7.229903] Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) [ 7.229906] 7880: ffff8007da834000 0001000000000000 [ 7.229909] 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d [ 7.229912] 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f [ 7.229915] 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 [ 7.229918] 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 [ 7.229921] 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 [ 7.229923] 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 [ 7.229926] 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 [ 7.229929] 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 [ 7.229932] 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f [ 7.229936] [<ffff0000081111a0>] lockdep_trace_alloc+0xe0/0xf0 [ 7.229940] [<ffff0000081f4950>] __kmalloc_track_caller+0x50/0x250 [ 7.229945] [<ffff00000857c088>] devres_alloc_node+0x28/0x60 [ 7.229949] [<ffff0000081220e0>] devm_request_threaded_irq+0x50/0xe0 [ 7.229955] [<ffff0000087e6220>] pcc_mbox_request_channel+0x110/0x170 [ 7.229960] [<ffff0000084b2660>] acpi_cppc_processor_probe+0x264/0x414 [ 7.229963] [<ffff0000084ae9f4>] __acpi_processor_start+0x28/0xa0 [ 7.229966] [<ffff0000084aeab0>] acpi_processor_start+0x44/0x54 [ 7.229970] [<ffff00000857897c>] driver_probe_device+0x1fc/0x2b0 [ 7.229974] [<ffff000008578ae4>] __driver_attach+0xb4/0xc0 [ 7.229977] [<ffff00000857683c>] bus_for_each_dev+0x5c/0xa0 [ 7.229980] [<ffff000008578110>] driver_attach+0x20/0x30 [ 7.229983] [<ffff000008577c20>] bus_add_driver+0x110/0x230 [ 7.229987] [<ffff000008579320>] driver_register+0x60/0x100 [ 7.229991] [<ffff000008d478b8>] acpi_processor_driver_init+0x2c/0xb0 [ 7.229996] [<ffff000008083168>] do_one_initcall+0x38/0x130 [ 7.230000] [<ffff000008d20d6c>] kernel_init_freeable+0x210/0x2b4 [ 7.230004] [<ffff000008945d90>] kernel_init+0x10/0x110 [ 7.230007] [<ffff000008082e80>] ret_from_fork+0x10/0x50 It's because the spinlock inside pcc_mbox_request_channel() is kept too long. This patch releases spinlock before request_irq() and free_irq() to fix this issue as spinlock is only needed to protect the channel data. Signed-off-by: Hoan Tran <hotran@apm.com> --- v3 * Free mailbox irq before reset the channel data * Free channel if it fails to request the mailbox irq v2 * Release spinlock before request_irq() and free_irq() instead of using mutex drivers/mailbox/pcc.c | 70 +++++++++++++++++++++++++-------------------------- 1 file changed, 35 insertions(+), 35 deletions(-)