[PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()

[PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()

[Martin Blumenstingl]

Use a 10000us AHB idle timeout in dwc2_core_reset() and make it
consistent with the other "wait for AHB master IDLE state" ocurrences.

This fixes a problem for me where dwc2 would not want to initialize when
updating to 4.19 on a MIPS Lantiq VRX200 SoC. dwc2 worked fine with
4.14.
Testing on my board shows that it takes 180us until AHB master IDLE
state is signalled. The very old vendor driver for this SoC (ifxhcd)
used a 1 second timeout.
Use the same timeout that is used everywhere when polling for
GRSTCTL_AHBIDLE instead of using a timeout that "works for one board"
(180us in my case) to have consistent behavior across the dwc2 driver.

Cc: linux-stable <stable@vger.kernel.org> # 4.19+
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/usb/dwc2/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index 8b499d643461..8e41d70fd298 100644
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -531,7 +531,7 @@ int dwc2_core_reset(struct dwc2_hsotg *hsotg, bool skip_wait)
 	}
 
 	/* Wait for AHB master IDLE state */
-	if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 50)) {
+	if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 10000)) {
 		dev_warn(hsotg->dev, "%s: HANG! AHB Idle timeout GRSTCTL GRSTCTL_AHBIDLE\n",
 			 __func__);
 		return -EBUSY;
-- 
2.22.0

Re: [PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()

[Minas Harutyunyan]

On 6/20/2019 9:51 PM, Martin Blumenstingl wrote:
> Use a 10000us AHB idle timeout in dwc2_core_reset() and make it
> consistent with the other "wait for AHB master IDLE state" ocurrences.
> 
> This fixes a problem for me where dwc2 would not want to initialize when
> updating to 4.19 on a MIPS Lantiq VRX200 SoC. dwc2 worked fine with
> 4.14.
> Testing on my board shows that it takes 180us until AHB master IDLE
> state is signalled. The very old vendor driver for this SoC (ifxhcd)
> used a 1 second timeout.
> Use the same timeout that is used everywhere when polling for
> GRSTCTL_AHBIDLE instead of using a timeout that "works for one board"
> (180us in my case) to have consistent behavior across the dwc2 driver.
> 
> Cc: linux-stable <stable@vger.kernel.org> # 4.19+
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> ---

Acked-by: Minas Harutyunyan <hminas@synopsys.com>

>   drivers/usb/dwc2/core.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
> index 8b499d643461..8e41d70fd298 100644
> --- a/drivers/usb/dwc2/core.c
> +++ b/drivers/usb/dwc2/core.c
> @@ -531,7 +531,7 @@ int dwc2_core_reset(struct dwc2_hsotg *hsotg, bool skip_wait)
>   	}
>   
>   	/* Wait for AHB master IDLE state */
> -	if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 50)) {
> +	if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 10000)) {
>   		dev_warn(hsotg->dev, "%s: HANG! AHB Idle timeout GRSTCTL GRSTCTL_AHBIDLE\n",
>   			 __func__);
>   		return -EBUSY;
> 

Re: [PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()

[Martin Blumenstingl]

On Mon, Jun 24, 2019 at 7:41 AM Minas Harutyunyan
<Minas.Harutyunyan@synopsys.com> wrote:
>
> On 6/20/2019 9:51 PM, Martin Blumenstingl wrote:
> > Use a 10000us AHB idle timeout in dwc2_core_reset() and make it
> > consistent with the other "wait for AHB master IDLE state" ocurrences.
> >
> > This fixes a problem for me where dwc2 would not want to initialize when
> > updating to 4.19 on a MIPS Lantiq VRX200 SoC. dwc2 worked fine with
> > 4.14.
> > Testing on my board shows that it takes 180us until AHB master IDLE
> > state is signalled. The very old vendor driver for this SoC (ifxhcd)
> > used a 1 second timeout.
> > Use the same timeout that is used everywhere when polling for
> > GRSTCTL_AHBIDLE instead of using a timeout that "works for one board"
> > (180us in my case) to have consistent behavior across the dwc2 driver.
> >
> > Cc: linux-stable <stable@vger.kernel.org> # 4.19+
> > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> > ---
>
> Acked-by: Minas Harutyunyan <hminas@synopsys.com>
thank you for reviewing this!

is there any chance we can get this fix into Linux 5.3? I know that
it's too late for 5.2 so I'm fine with skipping that.


Martin

Re: [PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()

[Martin Blumenstingl]

On Mon, Jul 1, 2019 at 7:54 PM Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
>
> On Mon, Jun 24, 2019 at 7:41 AM Minas Harutyunyan
> <Minas.Harutyunyan@synopsys.com> wrote:
> >
> > On 6/20/2019 9:51 PM, Martin Blumenstingl wrote:
> > > Use a 10000us AHB idle timeout in dwc2_core_reset() and make it
> > > consistent with the other "wait for AHB master IDLE state" ocurrences.
> > >
> > > This fixes a problem for me where dwc2 would not want to initialize when
> > > updating to 4.19 on a MIPS Lantiq VRX200 SoC. dwc2 worked fine with
> > > 4.14.
> > > Testing on my board shows that it takes 180us until AHB master IDLE
> > > state is signalled. The very old vendor driver for this SoC (ifxhcd)
> > > used a 1 second timeout.
> > > Use the same timeout that is used everywhere when polling for
> > > GRSTCTL_AHBIDLE instead of using a timeout that "works for one board"
> > > (180us in my case) to have consistent behavior across the dwc2 driver.
> > >
> > > Cc: linux-stable <stable@vger.kernel.org> # 4.19+
> > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> > > ---
> >
> > Acked-by: Minas Harutyunyan <hminas@synopsys.com>
> thank you for reviewing this!
>
> is there any chance we can get this fix into Linux 5.3? I know that
> it's too late for 5.2 so I'm fine with skipping that.
thank you Felipe for queuing this for v5.3!
for reference, this patch is now in the usb-for-v5.3-part2 tag: [0]


[0] https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git/commit/?h=usb-for-v5.3-part2&id=dfc4fdebc5d62ac4e2fe5428e59b273675515fb2

Re: [PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()

[Felipe Balbi]

Hi,

Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:

> On Mon, Jul 1, 2019 at 7:54 PM Martin Blumenstingl
> <martin.blumenstingl@googlemail.com> wrote:
>>
>> On Mon, Jun 24, 2019 at 7:41 AM Minas Harutyunyan
>> <Minas.Harutyunyan@synopsys.com> wrote:
>> >
>> > On 6/20/2019 9:51 PM, Martin Blumenstingl wrote:
>> > > Use a 10000us AHB idle timeout in dwc2_core_reset() and make it
>> > > consistent with the other "wait for AHB master IDLE state" ocurrences.
>> > >
>> > > This fixes a problem for me where dwc2 would not want to initialize when
>> > > updating to 4.19 on a MIPS Lantiq VRX200 SoC. dwc2 worked fine with
>> > > 4.14.
>> > > Testing on my board shows that it takes 180us until AHB master IDLE
>> > > state is signalled. The very old vendor driver for this SoC (ifxhcd)
>> > > used a 1 second timeout.
>> > > Use the same timeout that is used everywhere when polling for
>> > > GRSTCTL_AHBIDLE instead of using a timeout that "works for one board"
>> > > (180us in my case) to have consistent behavior across the dwc2 driver.
>> > >
>> > > Cc: linux-stable <stable@vger.kernel.org> # 4.19+
>> > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>> > > ---
>> >
>> > Acked-by: Minas Harutyunyan <hminas@synopsys.com>
>> thank you for reviewing this!
>>
>> is there any chance we can get this fix into Linux 5.3? I know that
>> it's too late for 5.2 so I'm fine with skipping that.
> thank you Felipe for queuing this for v5.3!
> for reference, this patch is now in the usb-for-v5.3-part2 tag: [0]
>
>
> [0] https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git/commit/?h=usb-for-v5.3-part2&id=dfc4fdebc5d62ac4e2fe5428e59b273675515fb2

I'll send pull request soon :-)

-- 
balbi