Commit 1cabff0d authored by Jonathan Cavitt's avatar Jonathan Cavitt Committed by Jani Nikula
Browse files

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


Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
parent 33978364

drivers/gpu/drm/i915/gvt/edid.c

+8 −10
Original line number Diff line number Diff line
@@ -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