From mboxrd@z Thu Jan 1 00:00:00 1970 From: walter harms Date: Thu, 13 Oct 2016 09:27:28 +0000 Subject: Re: [patch] drm/i915: fix a read size argument Message-Id: <57FF5380.1080704@bfs.de> List-Id: References: <20161013085508.GJ16198@mwanda> In-Reply-To: <20161013085508.GJ16198@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: intel-gfx@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter Am 13.10.2016 10:55, schrieb Dan Carpenter: > We want to read 3 bytes here, but because the parenthesis are in the > wrong place we instead read: > > sizeof(intel_dp->edp_dpcd) = sizeof(intel_dp->edp_dpcd) > > which is one byte. > > Fixes: fe5a66f91c88 ("drm/i915: Read PSR caps/intermediate freqs/etc. only once on eDP") > Signed-off-by: Dan Carpenter > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index 14a3cf0..ee8aa95 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -3551,8 +3551,8 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) > /* Read the eDP Display control capabilities registers */ > if ((intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) && > drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, > - intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd) = > - sizeof(intel_dp->edp_dpcd))) > + intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd)) = > + sizeof(intel_dp->edp_dpcd)) perhaps we can morph that into something more readable ? I would suggest: if (intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) { size_t size=sizeof(intel_dp->edp_dpcd); /* = EDP_DISPLAY_CTL_CAP_SIZE */ int ret; ret=drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV,intel_dp->edp_dpcd,size); if (ret != size ) ...... } this way it improves readability and reduces line length. > DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int) sizeof(intel_dp->edp_dpcd), > intel_dp->edp_dpcd); > > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >