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From:   Andrey Smirnov <andrew.smirnov@gmail.com>
Date:   Thu, 6 Jun 2019 12:18:44 -0700
Message-ID: <CAHQ1cqExJuKHcXBPszkMymzZg4r4nRKAoySPXLrCurOCoco9-g@mail.gmail.com>
Subject: Re: [PATCH v3 03/15] drm/bridge: tc358767: Simplify polling in tc_link_training()
To:     Andrzej Hajda <a.hajda@samsung.com>
Cc:     dri-devel@lists.freedesktop.org,
        Archit Taneja <architt@codeaurora.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Tomi Valkeinen <tomi.valkeinen@ti.com>,
        Andrey Gusakov <andrey.gusakov@cogentembedded.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Cory Tusar <cory.tusar@zii.aero>,
        Chris Healy <cphealy@gmail.com>,
        Lucas Stach <l.stach@pengutronix.de>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Thu, Jun 6, 2019 at 1:08 AM Andrzej Hajda <a.hajda@samsung.com> wrote:
>
> On 05.06.2019 09:04, Andrey Smirnov wrote:
> > Replace explicit polling in tc_link_training() with equivalent call to
> > tc_poll_timeout() for simplicity. No functional change intended (not
> > including slightly altered debug output).
> >
> > Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> > Cc: Archit Taneja <architt@codeaurora.org>
> > Cc: Andrzej Hajda <a.hajda@samsung.com>
> > Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
> > Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> > Cc: Andrey Gusakov <andrey.gusakov@cogentembedded.com>
> > Cc: Philipp Zabel <p.zabel@pengutronix.de>
> > Cc: Cory Tusar <cory.tusar@zii.aero>
> > Cc: Chris Healy <cphealy@gmail.com>
> > Cc: Lucas Stach <l.stach@pengutronix.de>
> > Cc: dri-devel@lists.freedesktop.org
> > Cc: linux-kernel@vger.kernel.org
> > ---
> >  drivers/gpu/drm/bridge/tc358767.c | 15 ++++++---------
> >  1 file changed, 6 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> > index 5e1e73a91696..115cffc55a96 100644
> > --- a/drivers/gpu/drm/bridge/tc358767.c
> > +++ b/drivers/gpu/drm/bridge/tc358767.c
> > @@ -748,22 +748,19 @@ static int tc_set_video_mode(struct tc_data *tc,
> >
> >  static int tc_wait_link_training(struct tc_data *tc)
> >  {
> > -     u32 timeout = 1000;
> >       u32 value;
> >       int ret;
> >
> > -     do {
> > -             udelay(1);
> > -             tc_read(DP0_LTSTAT, &value);
> > -     } while ((!(value & LT_LOOPDONE)) && (--timeout));
> > -
> > -     if (timeout == 0) {
> > +     ret = tc_poll_timeout(tc, DP0_LTSTAT, LT_LOOPDONE,
> > +                           LT_LOOPDONE, 1, 1000);
> > +     if (ret) {
> >               dev_err(tc->dev, "Link training timeout waiting for LT_LOOPDONE!\n");
> > -             return -ETIMEDOUT;
> > +             return ret;
> >       }
>
>
> Inconsistent coding, in previous patch you check (ret == -ETIMEDOUT) but
> not here. To simplify the code you can assume that tc_poll_timeout < 0,
> means timeout, in such case please adjust previous patch.
>

Sure, will do.

Thanks,
Andrey Smirnov