The patch below does not apply to the 5.19-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@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 08c59dde71b73a0ac94e3ed2d431345b01f20485 Mon Sep 17 00:00:00 2001 From: Jani Nikula jani.nikula@intel.com 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
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@vger.kernel.org # v4.19+ Cc: Ville Syrjala ville.syrjala@linux.intel.com Signed-off-by: Jani Nikula jani.nikula@intel.com Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20220520094600.2066945-1-jani....
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) {