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From: cong yang <yangcong5@huaqin.corp-partner.google.com>
Date: Wed, 8 May 2024 19:51:50 +0800
Message-ID: <CAHwB_NKPswAvE5TjRxWMR8LLV5sNuMmymXr4nhDc3r_AdRKr8A@mail.gmail.com>
Subject: Re: [PATCH v4 2/7] drm/panel: himax-hx83102: Break out as separate driver
To: Doug Anderson <dianders@chromium.org>
Cc: sam@ravnborg.org, neil.armstrong@linaro.org, daniel@ffwll.ch, 
	linus.walleij@linaro.org, krzysztof.kozlowski+dt@linaro.org, 
	robh+dt@kernel.org, conor+dt@kernel.org, airlied@gmail.com, 
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, 
	linux-kernel@vger.kernel.org, xuxinxiong@huaqin.corp-partner.google.com
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Hi,

Doug Anderson <dianders@chromium.org> =E4=BA=8E2024=E5=B9=B45=E6=9C=888=E6=
=97=A5=E5=91=A8=E4=B8=89 07:35=E5=86=99=E9=81=93=EF=BC=9A
>
> Hi,
>
> On Tue, May 7, 2024 at 6:53=E2=80=AFAM Cong Yang
> <yangcong5@huaqin.corp-partner.google.com> wrote:
> >
> > +static int hx83102_enable_extended_cmds(struct hx83102 *ctx, bool enab=
le)
> > +{
> > +       struct mipi_dsi_multi_context dsi_ctx =3D { .dsi =3D ctx->dsi }=
;
> > +
> > +       if (enable)
> > +               mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83102_SETEXTC,=
 0x83, 0x10, 0x21, 0x55, 0x00);
> > +       else
> > +               mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83102_SETEXTC,=
 0x00, 0x00, 0x00);
> > +
> > +       return 0;
>
> You're throwing away the error codes returned by the
> mipi_dsi_dcs_write_seq_multi(), which you shouldn't do. You have two
> options:
>
> Option #1: return dsi_ctx.accum_err here and then check the return
> value in callers.
>
> Option #2: instead of having this function take "struct hx83102 *ctx",
> just have it take "struct mipi_dsi_multi_context *dsi_ctx". Then it
> can return void and everything will be fine.
>
> I'd prefer option #2 but either is OK w/ me.

Ok,I will fix in V4, thanks.

>
>
> > +static int starry_himax83102_j02_init(struct hx83102 *ctx)
> > +{
> > +       struct mipi_dsi_multi_context dsi_ctx =3D { .dsi =3D ctx->dsi }=
;
> > +
> > +       hx83102_enable_extended_cmds(ctx, true);
> > +       mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83102_SETPOWER, 0x2c, =
0xb5, 0xb5, 0x31, 0xf1,
> > +                                        0x31, 0xd7, 0x2f, 0x36, 0x36, =
0x36, 0x36, 0x1a, 0x8b, 0x11,
> > +                                        0x65, 0x00, 0x88, 0xfa, 0xff, =
0xff, 0x8f, 0xff, 0x08, 0x74,
> > +                                        0x33);
>
> The indentation is still off here. You have 5 tabs followed by a
> space. To make things line up with the opening brace I think it should
> be 4 tabs followed by 5 spaces.

Sorry, my  editor 'Visual Studio Code' It seems that the correct indentatio=
n
is not recognized. I have checked it through the 'vim' editor in the V4 ver=
sion.
Thanks.

>
>
> > +static int hx83102_enable(struct drm_panel *panel)
> > +{
> > +       struct hx83102 *ctx =3D panel_to_hx83102(panel);
> > +       struct mipi_dsi_device *dsi =3D ctx->dsi;
> > +       struct device *dev =3D &dsi->dev;
> > +       int ret;
> > +
> > +       ret =3D ctx->desc->init(ctx);
> > +       if (ret)
> > +               return ret;
>
> You're still changing behavior here. In the old boe-tv101wum-nl6
> driver the init() function was invoked at the end of prepare(). Now
> you've got it at the beginning of enable(). If this change is
> important it should be in a separate commit and explained.
>
>
> > +       ret =3D mipi_dsi_dcs_exit_sleep_mode(dsi);
> > +       if (ret) {
> > +               dev_err(dev, "Failed to exit sleep mode: %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       msleep(120);
> > +
> > +       ret =3D mipi_dsi_dcs_set_display_on(dsi);
> > +       if (ret) {
> > +               dev_err(dev, "Failed to turn on the display: %d\n", ret=
);
> > +       }
>
> The old boe-tv101wum-nl6 driver didn't call
> mipi_dsi_dcs_exit_sleep_mode() nor mipi_dsi_dcs_set_display_on() in
> its enable routine, did it? If this change is important please put it
> in a separate change and justify it.

In the old boe-tv101wum-nl6 driver inital cmds was invoked at the end of
prepare() function , and call 0x11 and 0x29 at end of inital. For
himax-hx83102 driver, we move inital cmds invoked at enable() function.
For panel timing, I think there is no much difference. They are
all initial cmds executed after meeting the power-on sequence.
I will update these in the v4 commit message.

>
>
> -Doug