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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Andrzej Hajda <a.hajda@samsung.com>,
	Sasha Levin <sashal@kernel.org>,
	dri-devel@lists.freedesktop.org
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	[thread overview]
Message-ID: <20190209184952.127009-6-sashal@kernel.org> (raw)
In-Reply-To: <20190209184952.127009-1-sashal@kernel.org>

From: Tomi Valkeinen <tomi.valkeinen@ti.com>

[ 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>
---
 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


  parent reply	other threads:[~2019-02-09 18:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-09 18:49 [PATCH AUTOSEL 4.9 01/12] ACPI: NUMA: Use correct type for printing addresses on i386-PAE Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 02/12] cpufreq: check if policy is inactive early in __cpufreq_get() Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 03/12] drm/bridge: tc358767: add defines for DP1_SRCCTRL & PHY_2LANE Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 04/12] drm/bridge: tc358767: fix single lane configuration Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 05/12] drm/bridge: tc358767: fix initial DP0/1_SRCCTRL value Sasha Levin
2019-02-09 18:49 ` Sasha Levin [this message]
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 07/12] drm/bridge: tc358767: fix output H/V syncs Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 08/12] ARM: dts: da850-evm: Correct the sound card name Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 09/12] ARM: dts: da850-lcdk: " Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 10/12] ARM: dts: kirkwood: Fix polarity of GPIO fan lines Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 11/12] gpio: pl061: handle failed allocations Sasha Levin
2019-02-09 18:49 ` [PATCH AUTOSEL 4.9 12/12] cifs: Limit memory used by lock request calls to a page Sasha Levin

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