Re: [PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()
From: Martin Blumenstingl
Date: Wed Jul 03 2019 - 05:01:32 EST
On Mon, Jul 1, 2019 at 7:54 PM Martin Blumenstingl
> On Mon, Jun 24, 2019 at 7:41 AM Minas Harutyunyan
> <Minas.Harutyunyan@xxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx> # 4.19+
> > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> > > ---
> > Acked-by: Minas Harutyunyan <hminas@xxxxxxxxxxxx>
> 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: