[v3,03/15] drm/bridge: tc358767: Simplify polling in tc_link_training()

Submitted by Andrey Smirnov on June 5, 2019, 7:04 a.m.

Details

Message ID 20190605070507.11417-4-andrew.smirnov@gmail.com
State Accepted
Commit aa92213f388ba88f895cc8eb432b95925b890e3b
Headers show
Series "tc358767 driver improvements" ( rev: 3 ) in DRI devel

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Commit Message

Andrey Smirnov June 5, 2019, 7:04 a.m.
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(-)

Patch hide | download patch | download mbox

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;
 	}
 
-	return (value >> 8) & 0x7;
+	tc_read(DP0_LTSTAT, &value);
 
+	return (value >> 8) & 0x7;
 err:
 	return ret;
 }

Comments

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.


Beside this:

Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

 --
Regards
Andrzej


>  
> -	return (value >> 8) & 0x7;
> +	tc_read(DP0_LTSTAT, &value);
>  
> +	return (value >> 8) & 0x7;
>  err:
>  	return ret;
>  }
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