diff options
author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2020-09-04 14:53:43 +0300 |
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committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2020-09-17 17:12:15 +0300 |
commit | 42f2562ca1b52810415107d919535c552196384e (patch) | |
tree | 3f6740465dda61e743549a788eaca6727308451e /drivers/gpu/drm/drm_dp_helper.c | |
parent | 38784f6f880580cbe168edbe7ba38c161dee3216 (diff) | |
download | linux-42f2562ca1b52810415107d919535c552196384e.tar.xz |
drm/dp: Pimp drm_dp_downstream_max_bpc()
Deal with more cases in drm_dp_downstream_max_bpc():
- DPCD 1.0 -> assume 8bpc for non-DP
- DPCD 1.1+ DP (or DP++ with DP sink) -> allow anything
- DPCD 1.1+ TMDS -> check the caps, assume 8bpc if the value is crap
- anything else -> assume 8bpc
v2: Use Returns: for kdoc (Lyude)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-8-ville.syrjala@linux.intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
-rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 59 |
1 files changed, 36 insertions, 23 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 56a3ba147713..e1af400df65c 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -653,36 +653,44 @@ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], EXPORT_SYMBOL(drm_dp_downstream_max_clock); /** - * drm_dp_downstream_max_bpc() - extract branch device max + * drm_dp_downstream_max_bpc() - extract downstream facing port max * bits per component * @dpcd: DisplayPort configuration data - * @port_cap: port capabilities - * - * See also: - * drm_dp_read_downstream_info() - * drm_dp_downstream_max_clock() + * @port_cap: downstream facing port capabilities + * @edid: EDID * * Returns: Max bpc on success or 0 if max bpc not defined */ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], - const u8 port_cap[4]) + const u8 port_cap[4], + const struct edid *edid) { - int type = port_cap[0] & DP_DS_PORT_TYPE_MASK; - bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & - DP_DETAILED_CAP_INFO_AVAILABLE; - int bpc; - - if (!detailed_cap_info) + if (!drm_dp_is_branch(dpcd)) return 0; - switch (type) { - case DP_DS_PORT_TYPE_VGA: - case DP_DS_PORT_TYPE_DVI: - case DP_DS_PORT_TYPE_HDMI: + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_DP: + return 0; + default: + return 8; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return 0; case DP_DS_PORT_TYPE_DP_DUALMODE: - bpc = port_cap[2] & DP_DS_MAX_BPC_MASK; + if (is_edid_digital_input_dp(edid)) + return 0; + fallthrough; + case DP_DS_PORT_TYPE_HDMI: + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_VGA: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return 8; - switch (bpc) { + switch (port_cap[2] & DP_DS_MAX_BPC_MASK) { case DP_DS_8BPC: return 8; case DP_DS_10BPC: @@ -691,10 +699,12 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], return 12; case DP_DS_16BPC: return 16; + default: + return 8; } - fallthrough; + break; default: - return 0; + return 8; } } EXPORT_SYMBOL(drm_dp_downstream_max_bpc); @@ -717,12 +727,15 @@ EXPORT_SYMBOL(drm_dp_downstream_id); * @m: pointer for debugfs file * @dpcd: DisplayPort configuration data * @port_cap: port capabilities + * @edid: EDID * @aux: DisplayPort AUX channel * */ void drm_dp_downstream_debug(struct seq_file *m, const u8 dpcd[DP_RECEIVER_CAP_SIZE], - const u8 port_cap[4], struct drm_dp_aux *aux) + const u8 port_cap[4], + const struct edid *edid, + struct drm_dp_aux *aux) { bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE; @@ -789,7 +802,7 @@ void drm_dp_downstream_debug(struct seq_file *m, seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk); } - bpc = drm_dp_downstream_max_bpc(dpcd, port_cap); + bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, edid); if (bpc > 0) seq_printf(m, "\t\tMax bpc: %d\n", bpc); |