Commit 9a5bce69 authored Jan 03, 2019 by Tomi Valkeinen Committed by Greg Kroah-Hartman Feb 20, 2019

drm/bridge: tc358767: reject modes which require too much BW



[ 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@ti.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190103115954.12785-6-tomi.valkeinen@ti.com


Signed-off-by: Sasha Levin <sashal@kernel.org>

parent bfac24ce

drivers/gpu/drm/bridge/tc358767.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -1112,10 +1112,20 @@ 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;
		}