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

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

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc:stable@kernel.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 87ead090c7d5a5195af6cf8d15be5a5809ff9678..bc5a2c3382d92fbd10efca3f29f69a927e381fc0 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -98,6 +98,14 @@ static inline struct radeon_i2c_bus_rec radeon_lookup_i2c_gpio(struct radeon_dev
                                }
                        }
 
+                       /* 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;
@@ -174,6 +182,14 @@ void radeon_atombios_i2c_init(struct radeon_device *rdev)
                                }
                        }
 
+                       /* 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;
+                       }
+
                        i2c.mask_clk_reg = le16_to_cpu(gpio->usClkMaskRegisterIndex) * 4;
                        i2c.mask_data_reg = le16_to_cpu(gpio->usDataMaskRegisterIndex) * 4;
                        i2c.en_clk_reg = le16_to_cpu(gpio->usClkEnRegisterIndex) * 4;