Commit 5786e2c5 authored Aug 19, 2010 by Alex Deucher Committed by Dave Airlie Aug 20, 2010

drm/radeon/kms/DCE3+: switch pads to ddc mode when going i2c



The pins for ddc and aux are shared so you need to switch the
mode when doing ddc.  The ProcessAuxChannel table already sets
the pin mode to DP.  This should fix unreliable ddc issues
on DP ports using non-DP monitors.

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

parent 4e186b2d

drivers/gpu/drm/radeon/radeon_i2c.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -99,6 +99,13 @@ static void radeon_i2c_do_lock(struct radeon_i2c_chan *i2c, int lock_state)
		}
		}

		/* switch the pads to ddc mode */
		if (ASIC_IS_DCE3(rdev) && rec->hw_capable) {
		temp = RREG32(rec->mask_clk_reg);
		temp &= ~(1 << 16);
		WREG32(rec->mask_clk_reg, temp);
		}

		/* clear the output pin values */
		temp = RREG32(rec->a_clk_reg) & ~rec->a_clk_mask;
		WREG32(rec->a_clk_reg, temp);