linux-kernel - Re: [PATCH V3] drm/bridge: ti-sn65dsi86: Add support for DisplayPort mode with HPD

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] [day] [month] [year] [list]

Message-ID: <CAD=FV=VZ8=o3D4iQ+hMFKup+8LuUh74BOyf7YLX-VHRkcU7TrA@mail.gmail.com>
Date: Tue, 16 Sep 2025 07:30:35 -0700
From: Doug Anderson <dianders@...omium.org>
To: Dan Carpenter <dan.carpenter@...aro.org>
Cc: oe-kbuild@...ts.linux.dev, John Ripple <john.ripple@...sight.com>, lkp@...el.com, 
	oe-kbuild-all@...ts.linux.dev, Laurent.pinchart@...asonboard.com, 
	airlied@...il.com, andrzej.hajda@...el.com, blake.vermeer@...sight.com, 
	dri-devel@...ts.freedesktop.org, jernej.skrabec@...il.com, jonas@...boo.se, 
	linux-kernel@...r.kernel.org, maarten.lankhorst@...ux.intel.com, 
	matt_laubhan@...sight.com, mripard@...nel.org, neil.armstrong@...aro.org, 
	rfoss@...nel.org, simona@...ll.ch, tzimmermann@...e.de
Subject: Re: [PATCH V3] drm/bridge: ti-sn65dsi86: Add support for DisplayPort
 mode with HPD

Hi,

On Mon, Sep 15, 2025 at 10:46 PM Dan Carpenter <dan.carpenter@...aro.org> wrote:
>
> Hi John,
>
> kernel test robot noticed the following build warnings:
>
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/UPDATE-20250911-023707/John-Ripple/drm-bridge-ti-sn65dsi86-break-probe-dependency-loop/20250820-235209
> base:   linus/master
> patch link:    https://lore.kernel.org/r/20250910183353.2045339-1-john.ripple%40keysight.com
> patch subject: [PATCH V3] drm/bridge: ti-sn65dsi86: Add support for DisplayPort mode with HPD
> config: x86_64-randconfig-161-20250916 (https://download.01.org/0day-ci/archive/20250916/202509161344.FPfsjq01-lkp@intel.com/config)
> compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@...el.com>
> | Reported-by: Dan Carpenter <dan.carpenter@...aro.org>
> | Closes: https://lore.kernel.org/r/202509161344.FPfsjq01-lkp@intel.com/
>
> smatch warnings:
> drivers/gpu/drm/bridge/ti-sn65dsi86.c:1385 ti_sn_bridge_interrupt() error: uninitialized symbol 'status'.
>
> vim +/status +1385 drivers/gpu/drm/bridge/ti-sn65dsi86.c
>
> b8670cf7e6a41b John Ripple  2025-09-10  1365  static irqreturn_t ti_sn_bridge_interrupt(int irq, void *private)
> b8670cf7e6a41b John Ripple  2025-09-10  1366  {
> b8670cf7e6a41b John Ripple  2025-09-10  1367    struct ti_sn65dsi86 *pdata = private;
> b8670cf7e6a41b John Ripple  2025-09-10  1368    struct drm_device *dev = pdata->bridge.dev;
> b8670cf7e6a41b John Ripple  2025-09-10  1369    u8 status;
> b8670cf7e6a41b John Ripple  2025-09-10  1370    int ret;
> b8670cf7e6a41b John Ripple  2025-09-10  1371    bool hpd_event = false;
> b8670cf7e6a41b John Ripple  2025-09-10  1372
> b8670cf7e6a41b John Ripple  2025-09-10  1373    mutex_lock(&pdata->hpd_mutex);
> b8670cf7e6a41b John Ripple  2025-09-10  1374    if (!pdata->hpd_enabled) {
> b8670cf7e6a41b John Ripple  2025-09-10  1375            mutex_unlock(&pdata->hpd_mutex);
> b8670cf7e6a41b John Ripple  2025-09-10  1376            return IRQ_HANDLED;
> b8670cf7e6a41b John Ripple  2025-09-10  1377    }
> b8670cf7e6a41b John Ripple  2025-09-10  1378
> b8670cf7e6a41b John Ripple  2025-09-10  1379    ret = ti_sn65dsi86_read_u8(pdata, SN_IRQ_STATUS_REG, &status);
> b8670cf7e6a41b John Ripple  2025-09-10  1380    if (ret)
> b8670cf7e6a41b John Ripple  2025-09-10  1381            pr_err("Failed to read IRQ status: %d\n", ret);
>
> status isn't initialized on error.
>
> b8670cf7e6a41b John Ripple  2025-09-10  1382    else
> b8670cf7e6a41b John Ripple  2025-09-10  1383            hpd_event = status & (HPD_REMOVAL_STATUS | HPD_INSERTION_STATUS);
> b8670cf7e6a41b John Ripple  2025-09-10  1384
> b8670cf7e6a41b John Ripple  2025-09-10 @1385    if (status) {
>                                                     ^^^^^^
> warning

It looks like the bot reported this on an old version. The newest is
v7 [1] and things should be OK there. Yell if I missed something. :-)

[1] https:/lore.kernel.org/r/20250915174543.2564994-1-john.ripple@...sight.com