linux-kernel - Re: [PATCH 05/45] drm/msm/dp: add a helper to read mst caps for dp

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: <abxm6ppegxbesl6wztyxg46elhanh2mo5kxn43olbucw37cyon@aeqikyr4ord5>
Date: Wed, 28 May 2025 19:13:14 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Yongxing Mou <quic_yongmou@...cinc.com>
Cc: Abhinav Kumar <quic_abhinavk@...cinc.com>, Rob Clark <robdclark@...il.com>,
        Sean Paul <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
        Stephen Boyd <swboyd@...omium.org>,
        Chandan Uddaraju <chandanu@...eaurora.org>,
        Guenter Roeck <groeck@...omium.org>,
        Kuogee Hsieh <quic_khsieh@...cinc.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Vara Reddy <quic_varar@...cinc.com>,
        Rob Clark <robdclark@...omium.org>,
        Tanmay Shah <tanmay@...eaurora.org>, linux-arm-msm@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, freedreno@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
        Jessica Zhang <quic_jesszhan@...cinc.com>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>
Subject: Re: [PATCH 05/45] drm/msm/dp: add a helper to read mst caps for
 dp_panel

On Mon, May 26, 2025 at 08:26:47PM +0800, Yongxing Mou wrote:
> 
> 
> On 2024/12/6 16:52, Dmitry Baryshkov wrote:
> > On Thu, Dec 05, 2024 at 08:31:36PM -0800, Abhinav Kumar wrote:
> > > Add a helper to check whether a dp_panel is mst capable.
> > > 
> > > Signed-off-by: Abhinav Kumar <quic_abhinavk@...cinc.com>
> > > ---
> > >   drivers/gpu/drm/msm/dp/dp_aux.h   |  1 +
> > >   drivers/gpu/drm/msm/dp/dp_panel.c | 14 ++++++++++++++
> > >   drivers/gpu/drm/msm/dp/dp_panel.h |  1 +
> > >   3 files changed, 16 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_aux.h b/drivers/gpu/drm/msm/dp/dp_aux.h
> > > index 39c5b4c8596ab28d822493a6b4d479f5f786cdee..cb97a73cdd6ea74b612053bec578247a42214f23 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_aux.h
> > > +++ b/drivers/gpu/drm/msm/dp/dp_aux.h
> > > @@ -8,6 +8,7 @@
> > >   #include "dp_catalog.h"
> > >   #include <drm/display/drm_dp_helper.h>
> > > +#include <drm/display/drm_dp_mst_helper.h>
> > >   int msm_dp_aux_register(struct drm_dp_aux *msm_dp_aux);
> > >   void msm_dp_aux_unregister(struct drm_dp_aux *msm_dp_aux);
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
> > > index d277e9b2cbc03688976b6aa481ee724b186bab51..172de804dec445cb08ad8e3f058407f483cd6684 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_panel.c
> > > +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
> > > @@ -108,6 +108,20 @@ static u32 msm_dp_panel_get_supported_bpp(struct msm_dp_panel *msm_dp_panel,
> > >   	return min_supported_bpp;
> > >   }
> > > +bool msm_dp_panel_read_mst_cap(struct msm_dp_panel *msm_dp_panel)
> > > +{
> > > +	struct msm_dp_panel_private *panel;
> > > +
> > > +	if (!msm_dp_panel) {
> > > +		DRM_ERROR("invalid input\n");
> > > +		return 0;
> > > +	}
> > > +
> > > +	panel = container_of(msm_dp_panel, struct msm_dp_panel_private, msm_dp_panel);
> > > +
> > > +	return drm_dp_read_mst_cap(panel->aux, msm_dp_panel->dpcd);
> > 
> > So, it's a one-line wrapper. Do we actually need it?
> It beacuse the point of aux is in msm_dp_panel_private, so if we want to
> call drm_dp_read_mst_cap in other file, we need this wrapper.

It is being used from dp_display, which also ->aux pointer.

> > 
> > > +}
> > > +
> > >   int msm_dp_panel_read_link_caps(struct msm_dp_panel *msm_dp_panel,
> > >   				struct drm_connector *connector)
> > >   {
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
> > > index 7a38655c443af597c84fb78c6702b2a3ef9822ed..363b416e4cbe290f9c0e6171d6c0c5170f9fea62 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_panel.h
> > > +++ b/drivers/gpu/drm/msm/dp/dp_panel.h
> > > @@ -67,6 +67,7 @@ int msm_dp_panel_get_modes(struct msm_dp_panel *msm_dp_panel,
> > >   		struct drm_connector *connector);
> > >   void msm_dp_panel_handle_sink_request(struct msm_dp_panel *msm_dp_panel);
> > >   void msm_dp_panel_tpg_config(struct msm_dp_panel *msm_dp_panel, bool enable);
> > > +bool msm_dp_panel_read_mst_cap(struct msm_dp_panel *dp_panel);
> > >   /**
> > >    * is_link_rate_valid() - validates the link rate
> > > 
> > > -- 
> > > 2.34.1
> > > 
> > 
> 

-- 
With best wishes
Dmitry