drm/i915/gvt: Swap read and write checks

The function intel_gvt_i2c_handle_aux_ch_write currently does not
support the DP_AUX_I2C_WRITE operation.  Notably, we check if
op & 0x1 == DP_AUX_I2C_WRITE (one), and if it does not, assert that
op & 0x1 == DP_AUX_I2C_READ (zero).  This is unnecessary because if
op & 0x1 != 1, then op & 0x1 == 0.  But beyond that, it probably makes
more sense to check for the condition that is implemented, rather than
check for the condition that is not.

Swap the conditions.  We can also get rid of the unnecessary drm_WARN_ON
while we're here.

Suggested-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patch.msgid.link/20260204161945.8127-2-jonathan.cavitt@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/edid.c b/drivers/gpu/drm/i915/gvt/edid.c
index 021afff1cd5d44e713d0820fb0ed16ff0d0463c5..ca5b54466a65ce5dc8bb3a7c855c5646786784a1 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/edid.c
+++ b/drivers/gpu/drm/i915/gvt/edid.c
@@ -535,16 +535,7 @@ void intel_gvt_i2c_handle_aux_ch_write(struct intel_vgpu *vgpu,
                                        i2c_edid->edid_available = true;
                        }
                }
-       } else if ((op & 0x1) == DP_AUX_I2C_WRITE) {
-               /* TODO
-                * We only support EDID reading from I2C_over_AUX. And
-                * we do not expect the index mode to be used. Right now
-                * the WRITE operation is ignored. It is good enough to
-                * support the gfx driver to do EDID access.
-                */
-       } else {
-               if (drm_WARN_ON(&i915->drm, (op & 0x1) != DP_AUX_I2C_READ))
-                       return;
+       } else if ((op & 0x1) == DP_AUX_I2C_READ) {
                if (drm_WARN_ON(&i915->drm, msg_length != 4))
                        return;
                if (i2c_edid->edid_available && i2c_edid->target_selected) {
@@ -553,6 +544,13 @@ void intel_gvt_i2c_handle_aux_ch_write(struct intel_vgpu *vgpu,
                        aux_data_for_write = (val << 16);
                } else
                        aux_data_for_write = (0xff << 16);
+       } else {
+               /* TODO
+                * We only support EDID reading from I2C_over_AUX. And
+                * we do not expect the index mode to be used. Right now
+                * the WRITE operation is ignored. It is good enough to
+                * support the gfx driver to do EDID access.
+                */
        }
        /* write the return value in AUX_CH_DATA reg which includes:
         * ACK of I2C_WRITE