Commit 08c59dde authored by Jani Nikula's avatar Jani Nikula

drm/i915/dsi: fix VBT send packet port selection for ICL+

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 f915084e
("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: default avatarJani Nikula <jani.nikula@intel.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220520094600.2066945-1-jani.nikula@intel.com
parent 5f38c3fb
......@@ -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) {
......
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