> -----Original Message----- > From: Joel Stanley <joel@xxxxxxxxx> > Sent: Wednesday, December 23, 2020 9:07 AM > To: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>; Ryan Chen > <ryan_chen@xxxxxxxxxxxxxx> > Cc: Eddie James <eajames@xxxxxxxxxxxxx>; Mauro Carvalho Chehab > <mchehab@xxxxxxxxxx>; Andrew Jeffery <andrew@xxxxxxxx>; > linux-media@xxxxxxxxxxxxxxx; OpenBMC Maillist <openbmc@xxxxxxxxxxxxxxxx>; > Linux ARM <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; linux-aspeed > <linux-aspeed@xxxxxxxxxxxxxxxx>; Linux Kernel Mailing List > <linux-kernel@xxxxxxxxxxxxxxx>; Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx> > Subject: Re: [PATCH 2/3] aspeed-video: clear spurious interrupt bits > unconditionally > > On Tue, 22 Dec 2020 at 19:14, Zev Weiss <zev@xxxxxxxxxxxxxxxxx> wrote: > > > > On Mon, Dec 21, 2020 at 10:47:37PM CST, Joel Stanley wrote: > > >On Tue, 15 Dec 2020 at 02:46, Zev Weiss <zev@xxxxxxxxxxxxxxxxx> wrote: > > >> > > >> Instead of testing and conditionally clearing them one by one, we > > >> can instead just unconditionally clear them all at once. > > >> > > >> Signed-off-by: Zev Weiss <zev@xxxxxxxxxxxxxxxxx> > > > > > >I had a poke at the assembly and it looks like GCC is clearing the > > >bits unconditionally anyway, so removing the tests provides no change. > > > > > >Combining them is a good further optimization. > > > > > >Reviewed-by: Joel Stanley <joel@xxxxxxxxx> > > > > > >A question unrelated to this patch: Do you know why the driver > > >doesn't clear the status bits in the interrupt handler? I would > > >expect it to write the value of sts back to the register to ack the > > >pending interrupt. > > > > > > > No, I don't, and I was sort of wondering the same thing actually -- > > I'm not deeply familiar with this hardware or driver though, so I was > > a bit hesitant to start messing with things. (Though maybe doing so > > would address the "stickiness" aspect when it does manifest.) Perhaps > > Eddie or Jae can shed some light here? > > I think you're onto something here - this would be why the status bits seem to > stick until the device is reset. > > Until Aspeed can clarify if this is a hardware or software issue, I suggest we ack > the bits and log a message when we see them, instead of always ignoring them > without taking any action. > > Can you write a patch that changes the interrupt handler to ack status bits as it > handles each of them? > Hello Zev, before the patch, do you met issue with irq handler? [continuous incoming?] In aspeed_video_irq handler should only handle enable interrupt expected. u32 sts = aspeed_video_read(video, VE_INTERRUPT_STATUS); + sts &= aspeed_video_read(video, VE_INTERRUPT_CTRL); Ryan > > > > > > Zev > >
