The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 0ea917819d12fed41ea4662cc26ffa0060a5c354 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@xxxxxxxxx>
Date: Fri, 20 May 2022 12:46:00 +0300
Subject: [PATCH] drm/i915/dsi: fix VBT send packet port selection for ICL+
MIME-Version: 1.0
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The VBT send packet port selection was never updated for ICL+ where the
2nd link is on port B instead of port C as in VLV+ DSI.
First, single link DSI needs to use the configured port instead of
relying on the VBT sequence block port. Remove the hard-coded port C
check here and make it generic. For reference, see commit f915084edc5a
("drm/i915: Changes related to the sequence port no for") for the
original VLV specific fix.
Second, the sequence block port number is either 0 or 1, where 1
indicates the 2nd link. Remove the hard-coded port C here for 2nd
link. (This could be a "find second set bit" on DSI ports, but just
check the two possible options.)
Third, sanity check the result with a warning to avoid a NULL pointer
dereference.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5984
Cc: stable@xxxxxxxxxxxxxxx # v4.19+
Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220520094600.2066945-1-jani.nikula@xxxxxxxxx
(cherry picked from commit 08c59dde71b73a0ac94e3ed2d431345b01f20485)
diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
index f370e9c4350d..dd24aef925f2 100644
--- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
+++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
@@ -125,9 +125,25 @@ struct i2c_adapter_lookup {
#define ICL_GPIO_DDPA_CTRLCLK_2 8
#define ICL_GPIO_DDPA_CTRLDATA_2 9
-static enum port intel_dsi_seq_port_to_port(u8 port)
+static enum port intel_dsi_seq_port_to_port(struct intel_dsi *intel_dsi,
+ u8 seq_port)
{
- return port ? PORT_C : PORT_A;
+ /*
+ * If single link DSI is being used on any port, the VBT sequence block
+ * send packet apparently always has 0 for the port. Just use the port
+ * we have configured, and ignore the sequence block port.
+ */
+ if (hweight8(intel_dsi->ports) == 1)
+ return ffs(intel_dsi->ports) - 1;
+
+ if (seq_port) {
+ if (intel_dsi->ports & PORT_B)
+ return PORT_B;
+ else if (intel_dsi->ports & PORT_C)
+ return PORT_C;
+ }
+
+ return PORT_A;
}
static const u8 *mipi_exec_send_packet(struct intel_dsi *intel_dsi,
@@ -149,15 +165,10 @@ static const u8 *mipi_exec_send_packet(struct intel_dsi *intel_dsi,
seq_port = (flags >> MIPI_PORT_SHIFT) & 3;
- /* For DSI single link on Port A & C, the seq_port value which is
- * parsed from Sequence Block#53 of VBT has been set to 0
- * Now, read/write of packets for the DSI single link on Port A and
- * Port C will based on the DVO port from VBT block 2.
- */
- if (intel_dsi->ports == (1 << PORT_C))
- port = PORT_C;
- else
- port = intel_dsi_seq_port_to_port(seq_port);
+ port = intel_dsi_seq_port_to_port(intel_dsi, seq_port);
+
+ if (drm_WARN_ON(&dev_priv->drm, !intel_dsi->dsi_hosts[port]))
+ goto out;
dsi_device = intel_dsi->dsi_hosts[port]->device;
if (!dsi_device) {
