diff options
| author | Lee, Shawn C <shawn.c.lee@intel.com> | 2018-09-11 23:22:50 -0700 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2018-09-19 16:44:12 +0300 |
| commit | 53ca2edcf033f3368b2dc0ef3cbcc2f47d556d13 (patch) | |
| tree | c7a8b6e2c93bb03c8cd5b4d3eb5b68e2154a3fe0 /drivers/gpu/drm/drm_dp_helper.c | |
| parent | 0b49bbbd9f10dd5bcce126aa99041a44320767f7 (diff) | |
drm: Change limited M/N quirk to constant N quirk.
Some DP dongles in particular seem to be fussy about too large
link M/N values. Set specific value for N divider can resolve
this issue per dongle vendor's comment. So configure N as
constant value (0x8000) to instead of reduce M/N formula when
specific DP dongle connected.
v2: add more comments for issue description and fix typo.
v3: add lost commit messages back for version 2
v4: send patch to both intel-gfx and dri-devel
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Cc: Matt Atwood <matthew.s.atwood@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Clint Taylor <clinton.a.taylor@intel.com>
Tested-by: Clint Taylor <clinton.a.taylor@intel.com>
Signed-off-by: Lee, Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1536733371-25004-3-git-send-email-shawn.c.lee@intel.com
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 07167604e8cc..c1fe1713eaef 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1270,7 +1270,7 @@ struct dpcd_quirk { static const struct dpcd_quirk dpcd_quirk_list[] = { /* Analogix 7737 needs reduced M and N at HBR2 link rates */ - { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, + { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, }; #undef OUI |