Re: [PATCH 01/19] drm/bridge: cdns-mhdp8546: Improve error reporting in remove callback

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

[-- Attachment #1: Type: text/plain, Size: 2588 bytes --]

On Sun, Mar 19, 2023 at 03:13:01PM +0200, Laurent Pinchart wrote:
> Hi Uwe,
> 
> Thank you for the patch.
> 
> On Sat, Mar 18, 2023 at 08:07:46PM +0100, Uwe Kleine-König wrote:
> > Replace the generic error message issued by the driver core when the remove
> > callback returns non-zero ("remove callback returned a non-zero value. This
> > will be ignored.") by a message that tells the actual problem.
> > 
> > Also simplify a bit by checking the return value of wait_event_timeout a
> > bit later.
> > 
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > ---
> >  .../drm/bridge/cadence/cdns-mhdp8546-core.c    | 18 +++++++++---------
> >  1 file changed, 9 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> > index f6822dfa3805..d74c6fa30ccc 100644
> > --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
> > @@ -2574,7 +2574,6 @@ static int cdns_mhdp_remove(struct platform_device *pdev)
> >  {
> >  	struct cdns_mhdp_device *mhdp = platform_get_drvdata(pdev);
> >  	unsigned long timeout = msecs_to_jiffies(100);
> > -	bool stop_fw = false;
> >  	int ret;
> >  
> >  	drm_bridge_remove(&mhdp->bridge);
> > @@ -2582,18 +2581,19 @@ static int cdns_mhdp_remove(struct platform_device *pdev)
> >  	ret = wait_event_timeout(mhdp->fw_load_wq,
> >  				 mhdp->hw_state == MHDP_HW_READY,
> >  				 timeout);
> > -	if (ret == 0)
> > -		dev_err(mhdp->dev, "%s: Timeout waiting for fw loading\n",
> > -			__func__);
> > -	else
> > -		stop_fw = true;
> > -
> >  	spin_lock(&mhdp->start_lock);
> >  	mhdp->hw_state = MHDP_HW_STOPPED;
> >  	spin_unlock(&mhdp->start_lock);
> >  
> > -	if (stop_fw)
> > +	if (ret == 0) {
> > +		dev_err(mhdp->dev, "%s: Timeout waiting for fw loading\n",
> > +			__func__);
> > +	} else {
> >  		ret = cdns_mhdp_set_firmware_active(mhdp, false);
> > +		if (ret)
> > +			dev_err(mhdp->dev, "Failed to stop firmware (%pe)\n",
> > +				ERR_PTR(ret));
> 
> Why not simply
> 			dev_err(mhdp->dev, "Failed to stop firmware (%d)\n",
> 				ret);
> 
> ? Apart from that,

%pe is superior to %d because

	Failed to stop firmware (EIO)

is easier to understand for humans than

	Failed to stop firmware (-5)

. Don't you agree?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]