* [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers
@ 2018-02-26 10:56 Merlijn Wajer
2018-02-26 15:57 ` Bin Liu
0 siblings, 1 reply; 4+ messages in thread
From: Merlijn Wajer @ 2018-02-26 10:56 UTC (permalink / raw)
To: linux-omap
Cc: tony, merlijn, Bin Liu, Greg Kroah-Hartman, linux-usb, linux-kernel
Without pm_runtime_{get,put}_sync calls in place, reading
vbus status via /sys causes the following error:
Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060
pgd = b333e822
[fa0ab060] *pgd=48011452(bad)
[<c05261b0>] (musb_default_readb) from [<c0525bd0>] (musb_vbus_show+0x58/0xe4)
[<c0525bd0>] (musb_vbus_show) from [<c04c0148>] (dev_attr_show+0x20/0x44)
[<c04c0148>] (dev_attr_show) from [<c0259f74>] (sysfs_kf_seq_show+0x80/0xdc)
[<c0259f74>] (sysfs_kf_seq_show) from [<c0210bac>] (seq_read+0x250/0x448)
[<c0210bac>] (seq_read) from [<c01edb40>] (__vfs_read+0x1c/0x118)
[<c01edb40>] (__vfs_read) from [<c01edccc>] (vfs_read+0x90/0x144)
[<c01edccc>] (vfs_read) from [<c01ee1d0>] (SyS_read+0x3c/0x74)
[<c01ee1d0>] (SyS_read) from [<c0106fe0>] (ret_fast_syscall+0x0/0x54)
Solution was suggested by Tony Lindgren <tony@atomide.com>.
Signed-off-by: Merlijn Wajer <merlijn@wizzup.org>
---
drivers/usb/musb/musb_core.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index eef4ad578b31..ceaa40ef0e73 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1760,6 +1760,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
val = musb->a_wait_bcon;
vbus = musb_platform_get_vbus_status(musb);
if (vbus < 0) {
+ pm_runtime_get_sync(dev);
+
/* Use default MUSB method by means of DEVCTL register */
devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
if ((devctl & MUSB_DEVCTL_VBUS)
@@ -1767,6 +1769,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
vbus = 1;
else
vbus = 0;
+
+ pm_runtime_put_sync(dev);
}
spin_unlock_irqrestore(&musb->lock, flags);
--
2.16.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers
2018-02-26 10:56 [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers Merlijn Wajer
@ 2018-02-26 15:57 ` Bin Liu
2018-02-26 17:19 ` Merlijn Wajer
0 siblings, 1 reply; 4+ messages in thread
From: Bin Liu @ 2018-02-26 15:57 UTC (permalink / raw)
To: Merlijn Wajer
Cc: linux-omap, tony, Greg Kroah-Hartman, linux-usb, linux-kernel
Hi,
On Mon, Feb 26, 2018 at 11:56:08AM +0100, Merlijn Wajer wrote:
> Without pm_runtime_{get,put}_sync calls in place, reading
> vbus status via /sys causes the following error:
>
> Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060
> pgd = b333e822
> [fa0ab060] *pgd=48011452(bad)
>
> [<c05261b0>] (musb_default_readb) from [<c0525bd0>] (musb_vbus_show+0x58/0xe4)
> [<c0525bd0>] (musb_vbus_show) from [<c04c0148>] (dev_attr_show+0x20/0x44)
> [<c04c0148>] (dev_attr_show) from [<c0259f74>] (sysfs_kf_seq_show+0x80/0xdc)
> [<c0259f74>] (sysfs_kf_seq_show) from [<c0210bac>] (seq_read+0x250/0x448)
> [<c0210bac>] (seq_read) from [<c01edb40>] (__vfs_read+0x1c/0x118)
> [<c01edb40>] (__vfs_read) from [<c01edccc>] (vfs_read+0x90/0x144)
> [<c01edccc>] (vfs_read) from [<c01ee1d0>] (SyS_read+0x3c/0x74)
> [<c01ee1d0>] (SyS_read) from [<c0106fe0>] (ret_fast_syscall+0x0/0x54)
>
> Solution was suggested by Tony Lindgren <tony@atomide.com>.
>
> Signed-off-by: Merlijn Wajer <merlijn@wizzup.org>
> ---
> drivers/usb/musb/musb_core.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> index eef4ad578b31..ceaa40ef0e73 100644
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -1760,6 +1760,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
> val = musb->a_wait_bcon;
> vbus = musb_platform_get_vbus_status(musb);
> if (vbus < 0) {
> + pm_runtime_get_sync(dev);
> +
> /* Use default MUSB method by means of DEVCTL register */
> devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
> if ((devctl & MUSB_DEVCTL_VBUS)
> @@ -1767,6 +1769,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
> vbus = 1;
> else
> vbus = 0;
> +
> + pm_runtime_put_sync(dev);
> }
> spin_unlock_irqrestore(&musb->lock, flags);
Thanks for the patch, but I got spinlock deadlock when testing it. I
think the function pair should be at the outside scope of the
spin_lock/unlock, doesn't it?
Regards,
-Bin.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers
2018-02-26 15:57 ` Bin Liu
@ 2018-02-26 17:19 ` Merlijn Wajer
2018-02-26 17:38 ` Bin Liu
0 siblings, 1 reply; 4+ messages in thread
From: Merlijn Wajer @ 2018-02-26 17:19 UTC (permalink / raw)
To: Bin Liu, linux-omap, tony, Greg Kroah-Hartman, linux-usb, linux-kernel
[-- Attachment #1.1: Type: text/plain, Size: 2491 bytes --]
Hi,
On 26/02/18 16:57, Bin Liu wrote:
> Hi,
>
> On Mon, Feb 26, 2018 at 11:56:08AM +0100, Merlijn Wajer wrote:
>> Without pm_runtime_{get,put}_sync calls in place, reading
>> vbus status via /sys causes the following error:
>>
>> Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060
>> pgd = b333e822
>> [fa0ab060] *pgd=48011452(bad)
>>
>> [<c05261b0>] (musb_default_readb) from [<c0525bd0>] (musb_vbus_show+0x58/0xe4)
>> [<c0525bd0>] (musb_vbus_show) from [<c04c0148>] (dev_attr_show+0x20/0x44)
>> [<c04c0148>] (dev_attr_show) from [<c0259f74>] (sysfs_kf_seq_show+0x80/0xdc)
>> [<c0259f74>] (sysfs_kf_seq_show) from [<c0210bac>] (seq_read+0x250/0x448)
>> [<c0210bac>] (seq_read) from [<c01edb40>] (__vfs_read+0x1c/0x118)
>> [<c01edb40>] (__vfs_read) from [<c01edccc>] (vfs_read+0x90/0x144)
>> [<c01edccc>] (vfs_read) from [<c01ee1d0>] (SyS_read+0x3c/0x74)
>> [<c01ee1d0>] (SyS_read) from [<c0106fe0>] (ret_fast_syscall+0x0/0x54)
>>
>> Solution was suggested by Tony Lindgren <tony@atomide.com>.
>>
>> Signed-off-by: Merlijn Wajer <merlijn@wizzup.org>
>> ---
>> drivers/usb/musb/musb_core.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
>> index eef4ad578b31..ceaa40ef0e73 100644
>> --- a/drivers/usb/musb/musb_core.c
>> +++ b/drivers/usb/musb/musb_core.c
>> @@ -1760,6 +1760,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
>> val = musb->a_wait_bcon;
>> vbus = musb_platform_get_vbus_status(musb);
>> if (vbus < 0) {
>> + pm_runtime_get_sync(dev);
>> +
>> /* Use default MUSB method by means of DEVCTL register */
>> devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
>> if ((devctl & MUSB_DEVCTL_VBUS)
>> @@ -1767,6 +1769,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
>> vbus = 1;
>> else
>> vbus = 0;
>> +
>> + pm_runtime_put_sync(dev);
>> }
>> spin_unlock_irqrestore(&musb->lock, flags);
>
> Thanks for the patch, but I got spinlock deadlock when testing it. I
> think the function pair should be at the outside scope of the
> spin_lock/unlock, doesn't it?
I see - sorry. Weird, it worked for me on my Nokia N900. What did you
test this on?
I will try to submit an improved version tonight (you seem to have a
good idea on what is wrong, so I will follow that), but it would help me
if I can reproduce the issue.
Cheers,
Merlijn
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers
2018-02-26 17:19 ` Merlijn Wajer
@ 2018-02-26 17:38 ` Bin Liu
0 siblings, 0 replies; 4+ messages in thread
From: Bin Liu @ 2018-02-26 17:38 UTC (permalink / raw)
To: Merlijn Wajer
Cc: linux-omap, tony, Greg Kroah-Hartman, linux-usb, linux-kernel
On Mon, Feb 26, 2018 at 06:19:30PM +0100, Merlijn Wajer wrote:
> Hi,
>
> On 26/02/18 16:57, Bin Liu wrote:
> > Hi,
> >
> > On Mon, Feb 26, 2018 at 11:56:08AM +0100, Merlijn Wajer wrote:
> >> Without pm_runtime_{get,put}_sync calls in place, reading
> >> vbus status via /sys causes the following error:
> >>
> >> Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060
> >> pgd = b333e822
> >> [fa0ab060] *pgd=48011452(bad)
> >>
> >> [<c05261b0>] (musb_default_readb) from [<c0525bd0>] (musb_vbus_show+0x58/0xe4)
> >> [<c0525bd0>] (musb_vbus_show) from [<c04c0148>] (dev_attr_show+0x20/0x44)
> >> [<c04c0148>] (dev_attr_show) from [<c0259f74>] (sysfs_kf_seq_show+0x80/0xdc)
> >> [<c0259f74>] (sysfs_kf_seq_show) from [<c0210bac>] (seq_read+0x250/0x448)
> >> [<c0210bac>] (seq_read) from [<c01edb40>] (__vfs_read+0x1c/0x118)
> >> [<c01edb40>] (__vfs_read) from [<c01edccc>] (vfs_read+0x90/0x144)
> >> [<c01edccc>] (vfs_read) from [<c01ee1d0>] (SyS_read+0x3c/0x74)
> >> [<c01ee1d0>] (SyS_read) from [<c0106fe0>] (ret_fast_syscall+0x0/0x54)
> >>
> >> Solution was suggested by Tony Lindgren <tony@atomide.com>.
> >>
> >> Signed-off-by: Merlijn Wajer <merlijn@wizzup.org>
> >> ---
> >> drivers/usb/musb/musb_core.c | 4 ++++
> >> 1 file changed, 4 insertions(+)
> >>
> >> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> >> index eef4ad578b31..ceaa40ef0e73 100644
> >> --- a/drivers/usb/musb/musb_core.c
> >> +++ b/drivers/usb/musb/musb_core.c
> >> @@ -1760,6 +1760,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
> >> val = musb->a_wait_bcon;
> >> vbus = musb_platform_get_vbus_status(musb);
> >> if (vbus < 0) {
> >> + pm_runtime_get_sync(dev);
> >> +
> >> /* Use default MUSB method by means of DEVCTL register */
> >> devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
> >> if ((devctl & MUSB_DEVCTL_VBUS)
> >> @@ -1767,6 +1769,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf)
> >> vbus = 1;
> >> else
> >> vbus = 0;
> >> +
> >> + pm_runtime_put_sync(dev);
> >> }
> >> spin_unlock_irqrestore(&musb->lock, flags);
> >
> > Thanks for the patch, but I got spinlock deadlock when testing it. I
> > think the function pair should be at the outside scope of the
> > spin_lock/unlock, doesn't it?
>
> I see - sorry. Weird, it worked for me on my Nokia N900. What did you
> test this on?
>
> I will try to submit an improved version tonight (you seem to have a
> good idea on what is wrong, so I will follow that), but it would help me
> if I can reproduce the issue.
I tested on both Beaglebone Black and AM335x GP EVM, on the USB1 host
port. I didn't test the USB0 port (yet).
Thanks,
-Bin.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-02-26 10:56 [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers Merlijn Wajer
2018-02-26 15:57 ` Bin Liu
2018-02-26 17:19 ` Merlijn Wajer
2018-02-26 17:38 ` Bin Liu
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