[PATCH v3] drm/bridge: it6505: fix HDCP V match check is not performed correctly

[Dmitry Baryshkov]

On Fri, Jan 10, 2025 at 02:00:35AM +0000, Hermes.Wu at ite.com.tw wrote:
> hi
> 
> 
> -----Original Message-----
> From: Dmitry Baryshkov <dmitry.baryshkov at linaro.org> 
> Sent: Thursday, January 9, 2025 9:09 PM
> To: Hermes Wu (吳佳宏) <Hermes.Wu at ite.com.tw>
> Cc: Andrzej Hajda <andrzej.hajda at intel.com>; Neil Armstrong <neil.armstrong at linaro.org>; Robert Foss <rfoss at kernel.org>; Laurent Pinchart <Laurent.pinchart at ideasonboard.com>; Jonas Karlman <jonas at kwiboo.se>; Jernej Skrabec <jernej.skrabec at gmail.com>; Maarten Lankhorst <maarten.lankhorst at linux.intel.com>; Maxime Ripard <mripard at kernel.org>; Thomas Zimmermann <tzimmermann at suse.de>; David Airlie <airlied at gmail.com>; Simona Vetter <simona at ffwll.ch>; AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>; dri-devel at lists.freedesktop.org; linux-kernel at vger.kernel.org; Pet Weng (翁玉芬) <Pet.Weng at ite.com.tw>; Kenneth Hung (洪家倫) <Kenneth.Hung at ite.com.tw>; treapking at chromium.org
> Subject: Re: [PATCH v3] drm/bridge: it6505: fix HDCP V match check is not performed correctly
> 
> On Thu, Jan 09, 2025 at 02:40:08PM +0800, Hermes Wu via B4 Relay wrote:
> > From: Hermes Wu <Hermes.wu at ite.com.tw>
> > 
> > The loop of V compare is expected to iterate for 5 times which compare 
> > V array form av[0][] to av[4][].
> > It should check loop counter reach the last statement "i == 5"
> > before return true
> > 
> > Fixes: 0989c02c7a5c ("drm/bridge: it6505: fix HDCP CTS compare V 
> > matching")
> > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> >Excuse me, where did you get that from?? I didn't r-b it (yet).
> 
> Sorry,
> 
> I think I just missing understanding about this tag.
> I thought it should add if someone give advice to a path.
> 
> So I add it before you r-b it,

Okay. Please don't add extra tags in future.

The patch itself is:


Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>


> 
> > Signed-off-by: Hermes Wu <Hermes.wu at ite.com.tw>
> > ---
> > Changes in v3:
> > - The V value compare loop from i = 0 to i = 4 and shall exit with i == 5 
> >   if all V element matches
> > - Link to v2: 
> > https://lore.kernel.org/r/20250109-fix-hdcp-v-comp-v2-1-7dce0a59523f@i
> > te.com.tw
> > 
> > Changes in v2:
> > - pull the check of statment "i" out of V value check loop
> > - Link to v1: 
> > https://lore.kernel.org/r/20250108-fix-hdcp-v-comp-v1-1-9404811825cd@i
> > te.com.tw
> > ---
> >  drivers/gpu/drm/bridge/ite-it6505.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> >--
> >With best wishes
> >Dmitry
> 
> Br.
> Hermes

-- 
With best wishes
Dmitry