From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.9 06/12] drm/bridge: tc358767: reject modes which require too much BW Date: Sat, 9 Feb 2019 13:49:46 -0500 Message-ID: <20190209184952.127009-6-sashal@kernel.org> References: <20190209184952.127009-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190209184952.127009-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tomi Valkeinen , Andrzej Hajda , Sasha Levin , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org From: Tomi Valkeinen [ Upstream commit 51b9e62eb6950c762162ab7eb8390990179be067 ] The current driver accepts any videomode with pclk < 154MHz. This is not correct, as with 1 lane and/or 1.62Mbps speed not all videomodes can be supported. Add code to reject modes that require more bandwidth that is available. Signed-off-by: Tomi Valkeinen Reviewed-by: Andrzej Hajda Signed-off-by: Andrzej Hajda Link: https://patchwork.freedesktop.org/patch/msgid/20190103115954.12785-6-tomi.valkeinen@ti.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/bridge/tc358767.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index dbe403ea130d..16fa42984c50 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -1118,10 +1118,20 @@ static bool tc_bridge_mode_fixup(struct drm_bridge *bridge, static int tc_connector_mode_valid(struct drm_connector *connector, struct drm_display_mode *mode) { + struct tc_data *tc = connector_to_tc(connector); + u32 req, avail; + u32 bits_per_pixel = 24; + /* DPI interface clock limitation: upto 154 MHz */ if (mode->clock > 154000) return MODE_CLOCK_HIGH; + req = mode->clock * bits_per_pixel / 8; + avail = tc->link.base.num_lanes * tc->link.base.rate; + + if (req > avail) + return MODE_BAD; + return MODE_OK; } -- 2.19.1