drm/radeon/kms: fix up gpio i2c mask bits for r4xx

Fixes i2c test failures when i2c_algo_bit.bit_test=1.

The hw doesn't actually require a mask, so just set it
to the default mask bits for r1xx-r4xx radeon ddc.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index d2d179267af3fc878d210b40563e55c0a58eeac3..0a4ec1ed02c00ac268aed4bce842d45238c78eff 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -85,6 +85,18 @@ static struct radeon_i2c_bus_rec radeon_lookup_i2c_gpio(struct radeon_device *rd
                for (i = 0; i < num_indices; i++) {
                        gpio = &i2c_info->asGPIO_Info[i];
 
+                       /* r4xx mask is technically not used by the hw, so patch in the legacy mask bits */
+                       if ((rdev->family == CHIP_R420) ||
+                           (rdev->family == CHIP_R423) ||
+                           (rdev->family == CHIP_RV410)) {
+                               if ((le16_to_cpu(gpio->usClkMaskRegisterIndex) == 0x0018) ||
+                                   (le16_to_cpu(gpio->usClkMaskRegisterIndex) == 0x0019) ||
+                                   (le16_to_cpu(gpio->usClkMaskRegisterIndex) == 0x001a)) {
+                                       gpio->ucClkMaskShift = 0x19;
+                                       gpio->ucDataMaskShift = 0x18;
+                               }
+                       }
+
                        /* some evergreen boards have bad data for this entry */
                        if (ASIC_IS_DCE4(rdev)) {
                                if ((i == 7) &&