Hi Jani Nikula, thanks for reviewing, I'll use msleep instead, thanks! Xin > -----Original Message----- > From: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> > Sent: Thursday, September 21, 2023 8:09 PM > To: Xin Ji <xji@xxxxxxxxxxxxxxxx>; Andrzej Hajda <andrzej.hajda@xxxxxxxxx>; > Neil Armstrong <neil.armstrong@xxxxxxxxxx>; Robert Foss <rfoss@xxxxxxxxxx>; > Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>; Jonas Karlman > <jonas@xxxxxxxxx>; Jernej Skrabec <jernej.skrabec@xxxxxxxxx>; David Airlie > <airlied@xxxxxxxxx>; Daniel Vetter <daniel@xxxxxxxx> > Cc: Qilin Wen <qwen@xxxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; dri- > devel@xxxxxxxxxxxxxxxxxxxxx; hsinyi@xxxxxxxxxxxx; Bernie Liang > <bliang@xxxxxxxxxxxxxxxx>; Xin Ji <xji@xxxxxxxxxxxxxxxx> > Subject: Re: [PATCH] drm/bridge: Add 200ms delay to wait FW HPD status stable > > On Thu, 21 Sep 2023, Xin Ji <xji@xxxxxxxxxxxxxxxx> 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 <xji@xxxxxxxxxxxxxxxx> > > --- > > 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
