Hi Jani Nikula, thanks for reviewing, I'll use msleep instead, thanks! Xin
> -----Original Message----- > From: Jani Nikula <[email protected]> > Sent: Thursday, September 21, 2023 8:09 PM > To: Xin Ji <[email protected]>; Andrzej Hajda <[email protected]>; > Neil Armstrong <[email protected]>; Robert Foss <[email protected]>; > Laurent Pinchart <[email protected]>; Jonas Karlman > <[email protected]>; Jernej Skrabec <[email protected]>; David Airlie > <[email protected]>; Daniel Vetter <[email protected]> > Cc: Qilin Wen <[email protected]>; [email protected]; dri- > [email protected]; [email protected]; Bernie Liang > <[email protected]>; Xin Ji <[email protected]> > Subject: Re: [PATCH] drm/bridge: Add 200ms delay to wait FW HPD status stable > > On Thu, 21 Sep 2023, Xin Ji <[email protected]> wrote: > > For the none-interrupt design(sink device is panel, polling HPD status > > when chip power on), anx7625 FW has more than 200ms HPD de-bounce time > > in FW, for the safety to get HPD status, driver better to wait 200ms > > before HPD detection after OS resume back. > > > > Signed-off-by: Xin Ji <[email protected]> > > --- > > drivers/gpu/drm/bridge/analogix/anx7625.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c > > b/drivers/gpu/drm/bridge/analogix/anx7625.c > > index 51abe42c639e..833d6d50a03d 100644 > > --- a/drivers/gpu/drm/bridge/analogix/anx7625.c > > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c > > @@ -1464,6 +1464,9 @@ static int _anx7625_hpd_polling(struct > anx7625_data *ctx, > > if (ctx->pdata.intp_irq) > > return 0; > > > > + /* Delay 200ms for FW HPD de-bounce */ > > + usleep_range(200000, 201000); > > If you need to sleep for 200 ms, maybe use msleep instead? OK > > BR, > Jani. > > > + > > ret = readx_poll_timeout(anx7625_read_hpd_status_p0, > > ctx, val, > > ((val & HPD_STATUS) || (val < 0)), > > -- > Jani Nikula, Intel
