In some case, the dp link training success at 8.1Gbps, but the sink's
maximum supported rate is less than 8.1G. So change the default 8.1Gbps
link rate to the rate that reads from devices' capabilities.
Fixes: 54063d86e0 ("drm/hisilicon/hibmc: add dp link moduel in hibmc drivers")
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250813094238.3722345-6-shiyongbang@huawei.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Because the drm_aux of struct hibmc_dp_dev's member is not easy to get in
hibmc_drm_dp.c, move the drm_aux to struct hibmc_dp. Then there are some
adaptations and modifications to make this patch compile.
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250331074212.3370287-5-shiyongbang@huawei.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Add dp serdes cfg in link training process, and related adapting
and modificating. Change some init values about training, because we want
completely to negotiation process, so we start with the maximum rate and
the electrical characteristic level is 0. Because serdes default cfgs is
changed and used in hibmc_kms_init(), we changed the if-statement to check
whether the value is 0.
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250331074212.3370287-4-shiyongbang@huawei.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
drm_dp_dpcd_read_link_status() follows the "return error code or number
of bytes read" protocol, with the code returning less bytes than
requested in case of some errors. However most of the drivers
interpreted that as "return error code in case of any error". Switch
drm_dp_dpcd_read_link_status() to drm_dp_dpcd_read_data() and make it
follow that protocol too.
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250324-drm-rework-dpcd-access-v4-2-e80ff89593df@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Add link training process functions in this moduel.
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Tian Tao <tiantao6@hisilicon.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250103093824.1963816-3-shiyongbang@huawei.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
