drm/radeon/kms/evergreen: work around bad data in some i2c tables

The 7th entry in a lot of evergreen i2c gpio tables is partially
zeroed.  Fix the entry.

Should fix the missing ddc entry in:
https://bugs.freedesktop.org/show_bug.cgi?id=29255

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_atombios.c

@@ -85,6 +85,19 @@ 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 evergreen boards have bad data for this entry */
+			if (ASIC_IS_DCE4(rdev)) {
+				if ((i == 7) &&
+				    (gpio->usClkMaskRegisterIndex == 0x1936) &&
+				    (gpio->sucI2cId.ucAccess == 0)) {
+					gpio->sucI2cId.ucAccess = 0x97;
+					gpio->ucDataMaskShift = 8;
+					gpio->ucDataEnShift = 8;
+					gpio->ucDataY_Shift = 8;
+					gpio->ucDataA_Shift = 8;
+				}
+			}
+
 			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;
@@ -147,6 +160,20 @@ void radeon_atombios_i2c_init(struct radeon_device *rdev)
 		for (i = 0; i < num_indices; i++) {
 			gpio = &i2c_info->asGPIO_Info[i];
 			i2c.valid = false;
+
+			/* some evergreen boards have bad data for this entry */
+			if (ASIC_IS_DCE4(rdev)) {
+				if ((i == 7) &&
+				    (gpio->usClkMaskRegisterIndex == 0x1936) &&
+				    (gpio->sucI2cId.ucAccess == 0)) {
+					gpio->sucI2cId.ucAccess = 0x97;
+					gpio->ucDataMaskShift = 8;
+					gpio->ucDataEnShift = 8;
+					gpio->ucDataY_Shift = 8;
+					gpio->ucDataA_Shift = 8;
+				}
+			}
+
 			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;