From: Tomi Valkeinen <tomi.valkeinen@xxxxxx> [ 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 <tomi.valkeinen@xxxxxx> Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20190103115954.12785-6-tomi.valkeinen@xxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 ab299f4debfa..a1f3dd2afbb1 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -1114,10 +1114,20 @@ static bool tc_bridge_mode_fixup(struct drm_bridge *bridge, static enum drm_mode_status 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
