Re: [PATCH v5 20/34] drm/mediatek: mtk_hdmi: Use dev_err_probe() in mtk_hdmi_dt_parse_pdata()

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

On Mon, 2025-01-27 at 12:42 +0100, AngeloGioacchino Del Regno wrote:
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> 
> Il 24/01/25 09:24, CK Hu (胡俊光) ha scritto:
> > Hi, Angelo:
> > 
> > On Mon, 2025-01-13 at 15:52 +0100, AngeloGioacchino Del Regno wrote:
> > > External email : Please do not click links or open attachments until you have verified the sender or the content.
> > > 
> > > 
> > > Change error prints to use dev_err_probe() instead of dev_err()
> > > where possible in function mtk_hdmi_dt_parse_pdata(), used only
> > > during device probe.
> > > While at it, also beautify some prints.
> > 
> > I think you have do two things.
> > The first one is "Use dev_err_probe() in mtk_hdmi_dt_parse_pdata()" as the title says.
> > The second one is "beautify some prints".
> > 
> > The title does not mention the second one, so I think the second one is not related to this patch.
> 
> The beautification is a consequence of changing to dev_err_probe() - and this is
> because dev_err_probe auto-formats the error code into the print, so all of the
> ": %d" was removed *because* of the migration to that.
> 
> The only string that had changes that are not consequence of that is
> "Failed to find ddc-i2c-bus node in %pOF -> No ddc-i2c-bus in connector"
> 
> Besides, 99.99% of the change here is using dev_err_probe() instead of dev_err(),
> I'm not sure that mentioning that one string out of five changed in the commit
> description is actually worth it.
> 
> I've mentioned that in the commit description though, and looks enough to me, so
> I'm not sure why you think that the one string change should go to the title.
> That is also because ddc-i2c-bus can only be defined in one node, so the print
> was actually stating the obvious.
> 
> > You think some refinement is not worth to be a patch.
> 
> Correct, and that's because it's one single string out of five.
> One commit to change one string simply clutters the log without bringing any
> commit readability benefits at all.
> 
> > If it's not worth, maybe we should keep them as they are.
> > Or you could collect all refinement into one refinement patch, and this would looks worth.
> 
> That's what I've done in one of the previous versions.
> 
> You rightfully wanted me to split (and yeah I agree it's better), so that's the
> split patches. I really don't think that splitting more is any beneficial, as
> much as I don't think that reverting back to the non-split version is.
> 
> That ... unless I've misunderstood what you're saying here? :-)
> 
> Cheers,
> Angelo
> 
> > 
> > Regards,
> > CK
> > 
> > > 
> > > Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> > > ---
> > >   drivers/gpu/drm/mediatek/mtk_hdmi.c | 34 ++++++++++-------------------
> > >   1 file changed, 11 insertions(+), 23 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> > > index 65e9629b6b77..48c37294dcbb 100644
> > > --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
> > > +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> > > @@ -1372,30 +1372,23 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
> > >   {
> > >          struct device *dev = &pdev->dev;
> > >          struct device_node *np = dev->of_node;
> > > -       struct device_node *cec_np, *remote, *i2c_np;
> > > +       struct device_node *remote, *i2c_np;
> > >          struct platform_device *cec_pdev;
> > >          struct regmap *regmap;
> > >          int ret;
> > > 
> > >          ret = mtk_hdmi_get_all_clk(hdmi, np);
> > > -       if (ret) {
> > > -               if (ret != -EPROBE_DEFER)
> > > -                       dev_err(dev, "Failed to get clocks: %d\n", ret);
> > > -
> > > -               return ret;
> > > -       }
> > > +       if (ret)
> > > +               return dev_err_probe(dev, ret, "Failed to get clocks\n");
> > > 
> > >          /* The CEC module handles HDMI hotplug detection */
> > >          cec_np = of_get_compatible_child(np->parent, "mediatek,mt8173-cec");
> > > -       if (!cec_np) {
> > > -               dev_err(dev, "Failed to find CEC node\n");
> > > -               return -EINVAL;
> > > -       }
> > > +       if (!cec_np)
> > > +               return dev_err_probe(dev, -EINVAL, "Failed to find CEC node\n");
> > > 
> > >          cec_pdev = of_find_device_by_node(cec_np);
> > >          if (!cec_pdev) {
> > > -               dev_err(hdmi->dev, "Waiting for CEC device %pOF\n",
> > > -                       cec_np);
> > > +               dev_err(hdmi->dev, "Waiting for CEC device %pOF\n", cec_np);

This modification does not use dev_err_probe() and just beautify code, so I think this is not related to the title.

> > >                  of_node_put(cec_np);
> > >                  return -EPROBE_DEFER;
> > >          }
> > > @@ -1413,9 +1406,8 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
> > >          if (IS_ERR(regmap))
> > >                  ret = PTR_ERR(regmap);
> > >          if (ret) {
> > > -               dev_err(dev,
> > > -                       "Failed to get system configuration registers: %d\n",
> > > -                       ret);
> > > +               dev_err_probe(dev, ret,
> > > +                             "Failed to get system configuration registers\n");
> > >                  goto put_device;
> > >          }
> > >          hdmi->sys_regmap = regmap;
> > > @@ -1443,20 +1435,16 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
> > >          }
> > > 
> > >          i2c_np = of_parse_phandle(remote, "ddc-i2c-bus", 0);
> > > +       of_node_put(remote);
> > >          if (!i2c_np) {
> > > -               dev_err(dev, "Failed to find ddc-i2c-bus node in %pOF\n",
> > > -                       remote);
> > > -               of_node_put(remote);
> > > -               ret = -EINVAL;
> > > +               ret = dev_err_probe(dev, -EINVAL, "No ddc-i2c-bus in connector\n");

This print modification is OK for me because it's related to using dev_err_probe().

Regards,
CK

> > >                  goto put_device;
> > >          }
> > > -       of_node_put(remote);
> > > 
> > >          hdmi->ddc_adpt = of_find_i2c_adapter_by_node(i2c_np);
> > >          of_node_put(i2c_np);
> > >          if (!hdmi->ddc_adpt) {
> > > -               dev_err(dev, "Failed to get ddc i2c adapter by node\n");
> > > -               ret = -EINVAL;
> > > +               ret = dev_err_probe(dev, -EINVAL, "Failed to get ddc i2c adapter by node\n");
> > >                  goto put_device;
> > >          }
> > > 
> > > --
> > > 2.47.0
> > > 
> > 
> 
> 
> --
> AngeloGioacchino Del Regno
> Senior Software Engineer
> 
> Collabora Ltd.
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