linux-kernel - Re: [PATCH 11/17] drm: renesas: rz-du: mipi

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CA+V-a8v0K_tWA=LnyHDptoBjtgPHSbgwpJp4L1rw4Uv6KC+-JA@mail.gmail.com>
Date: Mon, 31 Mar 2025 14:58:45 +0100
From: "Lad, Prabhakar" <prabhakar.csengg@...il.com>
To: Biju Das <biju.das.jz@...renesas.com>
Cc: Geert Uytterhoeven <geert+renesas@...der.be>, Andrzej Hajda <andrzej.hajda@...el.com>, 
	Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>, 
	"laurent.pinchart" <laurent.pinchart@...asonboard.com>, Jonas Karlman <jonas@...boo.se>, 
	Jernej Skrabec <jernej.skrabec@...il.com>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
	Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Mauro Carvalho Chehab <mchehab@...nel.org>, 
	Kieran Bingham <kieran.bingham+renesas@...asonboard.com>, Stephen Boyd <sboyd@...nel.org>, 
	Philipp Zabel <p.zabel@...gutronix.de>, 
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>, 
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, 
	"linux-renesas-soc@...r.kernel.org" <linux-renesas-soc@...r.kernel.org>, 
	"linux-media@...r.kernel.org" <linux-media@...r.kernel.org>, 
	"linux-clk@...r.kernel.org" <linux-clk@...r.kernel.org>, 
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>, 
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: Re: [PATCH 11/17] drm: renesas: rz-du: mipi_dsi: Add OF data support

Hi Biju,

Thank you for the review.

On Mon, Mar 31, 2025 at 1:38 PM Biju Das <biju.das.jz@...renesas.com> wrote:
>
> Hi Prabhakar,
>
> Thanks for the patch.
>
> > -----Original Message-----
> > From: Prabhakar <prabhakar.csengg@...il.com>
> > Sent: 30 March 2025 22:07
> > Subject: [PATCH 11/17] drm: renesas: rz-du: mipi_dsi: Add OF data support
> >
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
> >
> > In preparation for adding support for the Renesas RZ/V2H(P) SoC, this patch introduces a mechanism to
> > pass SoC-specific information via OF data in the DSI driver. This enables the driver to adapt
> > dynamically to various SoC-specific requirements without hardcoding configurations.
> >
> > The MIPI DSI interface on the RZ/V2H(P) SoC is nearly identical to the one on the RZ/G2L SoC. While
> > the LINK registers are shared between the two SoCs, the D-PHY registers differ. Also the VCLK range
> > differs on both these SoCs. To accommodate these differences `struct rzg2l_mipi_dsi_hw_info` is
> > introduced and as now passed as OF data.
> >
> > These changes lay the groundwork for the upcoming RZ/V2H(P) SoC support by allowing SoC-specific data
> > to be passed through OF.
> >
<snip>
> > +
> >       ret = drm_of_get_data_lanes_count_ep(dsi->dev->of_node, 1, 0, 1, 4);
> >       if (ret < 0)
> >               return dev_err_probe(dsi->dev, ret,
> > @@ -729,10 +750,12 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
> >       if (IS_ERR(dsi->vclk))
> >               return PTR_ERR(dsi->vclk);
> >
> > -     dsi->rstc = devm_reset_control_get_exclusive(dsi->dev, "rst");
> > -     if (IS_ERR(dsi->rstc))
> > -             return dev_err_probe(dsi->dev, PTR_ERR(dsi->rstc),
> > -                                  "failed to get rst\n");
> > +     if (dsi->info->has_dphy_rstc) {
> > +             dsi->rstc = devm_reset_control_get_exclusive(dsi->dev, "rst");
>
> Maybe use devm_reset_control_get_optional_exclusive by dropping has_dphy_rstc.
>
As the dtbs_check doesn't enforce this,  `has_dphy_rstc` flag was
added. Recently the same was done for the CRU [0] based on the recent
comment received.

[0] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20250328173032.423322-10-tommaso.merciai.xr@bp.renesas.com/

Cheers,
Prabhakar