Merge tag 'drm-intel-next-2024-02-27-1' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

drm/i915 feature pull #2 for v6.9:

Features and functionality:
- DP tunneling and bandwidth allocation support (Imre)
- Add more ADL-N PCI IDs (Gustavo)
- Enable fastboot also on older platforms (Ville)
- Bigjoiner force enable debugfs option for testing (Stan)

Refactoring and cleanups:
- Remove unused structs and struct members (Jiri Slaby)
- Use per-device debug logging (Ville)
- State check improvements (Ville)
- Hardcoded cd2x divider cleanups (Ville)
- CDCLK documentation updates (Ville, Rodrigo)

Fixes:
- HDCP MST Type1 fixes (Suraj)
- Fix MTL C20 PHY PLL values (Ravi)
- More hardware access prevention during init (Imre)
- Always enable decompression with tile4 on Xe2 (Juha-Pekka)
- Improve LNL package C residency (Suraj)

drm core changes:
- DP tunneling and bandwidth allocation helpers (Imre)

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/87sf1devbj.fsf@intel.com

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 8d6ce46471ae..d046dfa79504 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -4055,3 +4055,33 @@ int drm_dp_bw_channel_coding_efficiency(bool is_uhbr)
 		return 800000;
 }
 EXPORT_SYMBOL(drm_dp_bw_channel_coding_efficiency);
+
+/**
+ * drm_dp_max_dprx_data_rate - Get the max data bandwidth of a DPRX sink
+ * @max_link_rate: max DPRX link rate in 10kbps units
+ * @max_lanes: max DPRX lane count
+ *
+ * Given a link rate and lanes, get the data bandwidth.
+ *
+ * Data bandwidth is the actual payload rate, which depends on the data
+ * bandwidth efficiency and the link rate.
+ *
+ * Note that protocol layers above the DPRX link level considered here can
+ * further limit the maximum data rate. Such layers are the MST topology (with
+ * limits on the link between the source and first branch device as well as on
+ * the whole MST path until the DPRX link) and (Thunderbolt) DP tunnels -
+ * which in turn can encapsulate an MST link with its own limit - with each
+ * SST or MST encapsulated tunnel sharing the BW of a tunnel group.
+ *
+ * Returns the maximum data rate in kBps units.
+ */
+int drm_dp_max_dprx_data_rate(int max_link_rate, int max_lanes)
+{
+	int ch_coding_efficiency =
+		drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(max_link_rate));
+
+	return DIV_ROUND_DOWN_ULL(mul_u32_u32(max_link_rate * 10 * max_lanes,
+					      ch_coding_efficiency),
+				  1000000 * 8);
+}
+EXPORT_SYMBOL(drm_dp_max_dprx_data_rate);