From: Alex Deucher Date: Mon, 9 Sep 2013 14:54:22 +0000 (-0400) Subject: drm/radeon/atom: workaround vbios bug in transmitter table on rs880 (v2) X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=91f3a6aaf280294b07c05dfe606e6c27b7ba3c72;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git drm/radeon/atom: workaround vbios bug in transmitter table on rs880 (v2) The OUTPUT_ENABLE action jumps past the point in the coder where the data_offset is set on certain rs780 cards. This worked previously because the OUTPUT_ENABLE action is always called immediately after the ENABLE action so the data_offset remained set. In 6f8bbaf568c7f2c497558bfd04654c0b9841ad57 (drm/radeon/atom: initialize more atom interpretor elements to 0), we explictly reset data_offset to 0 between atom calls which then caused this to fail. The fix is to just skip calling the OUTPUT_ENABLE action on the problematic chipsets. The ENABLE action does the same thing and more. Ultimately, we could probably drop the OUTPUT_ENABLE action all together on DCE3 asics. fixes: https://bugzilla.kernel.org/show_bug.cgi?id=60791 v2: only rs880 seems to be affected Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org --- diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c index 9166e0b95a0a..32923d2f6002 100644 --- a/drivers/gpu/drm/radeon/atombios_encoders.c +++ b/drivers/gpu/drm/radeon/atombios_encoders.c @@ -1650,8 +1650,12 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode) atombios_dig_encoder_setup(encoder, ATOM_ENABLE, 0); atombios_dig_transmitter_setup(encoder, ATOM_TRANSMITTER_ACTION_SETUP, 0, 0); atombios_dig_transmitter_setup(encoder, ATOM_TRANSMITTER_ACTION_ENABLE, 0, 0); - /* some early dce3.2 boards have a bug in their transmitter control table */ - if ((rdev->family != CHIP_RV710) && (rdev->family != CHIP_RV730)) + /* some dce3.x boards have a bug in their transmitter control table. + * ACTION_ENABLE_OUTPUT can probably be dropped since ACTION_ENABLE + * does the same thing and more. + */ + if ((rdev->family != CHIP_RV710) && (rdev->family != CHIP_RV730) && + (rdev->family != CHIP_RS880)) atombios_dig_transmitter_setup(encoder, ATOM_TRANSMITTER_ACTION_ENABLE_OUTPUT, 0, 0); } if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {