drm/radeon/kms: add workaround for dce3 ddc line vbios bug

commit 3074adc8b6d9bf28b574a58241b958057a69a7a0 upstream.

fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=23752

[AK: Dropped hunk for non existing i2c code in .35]
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index d7c18e5233e5c5e7eeeca5c469462727229d853d..42d876a5751b4ccaa4143c94e031b8e1b58bb9e1 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -84,6 +84,14 @@ static inline struct radeon_i2c_bus_rec radeon_lookup_i2c_gpio(struct radeon_dev
                for (i = 0; i < num_indices; i++) {
                        gpio = &i2c_info->asGPIO_Info[i];
 
+                       /* some DCE3 boards have bad data for this entry */
+                       if (ASIC_IS_DCE3(rdev)) {
+                               if ((i == 4) &&
+                                   (gpio->usClkMaskRegisterIndex == 0x1fda) &&
+                                   (gpio->sucI2cId.ucAccess == 0x94))
+                                       gpio->sucI2cId.ucAccess = 0x14;
+                       }
+
                        if (gpio->sucI2cId.ucAccess == id) {
                                i2c.mask_clk_reg = le16_to_cpu(gpio->usClkMaskRegisterIndex) * 4;
                                i2c.mask_data_reg = le16_to_cpu(gpio->usDataMaskRegisterIndex) * 4;