[PATCH 06/32] drm/i915/xe3p_lpd: Update bandwidth parameters

[Gustavo Sousa <gustavo.sousa@intel.com>]

From: Matt Atwood <matthew.s.atwood@intel.com>

Bandwidth parameters for Xe3p_LPD are basically the same as for Xe3_LPD.
However, now Xe3p_LPD has the ecc_impacting_de field, which could impact
how the derating is defined.

For the cases where that field is true, we use xe3p_lpd_ecc_sa_info,
similarly to what was done for Xe2_HPD.  Note, however, that Bspec
specifies the ECC derating value only for GDDR memory.  For now, we just
re-use the value that was defined for Xe2_HPD, namely 45.  We need to
confirm with the hardware team what would be the correct value(s) to use
for the ECC case.

Bspec: 68859, 69131
Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
---
 drivers/gpu/drm/i915/display/intel_bw.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index 8f5b86cd91b6..f0940ff9d19b 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -461,6 +461,20 @@ static const struct intel_sa_info xe3lpd_3002_sa_info = {
 	.derating = 10,
 };
 
+static const struct intel_sa_info xe3p_lpd_ecc_sa_info = {
+	.deburst = 32,
+	.deprogbwlimit = 65, /* GB/s */
+	.displayrtids = 256,
+	/*
+	 * FIXME: The Bspec only shows that derating for ECC should be 45 for
+	 * GDDR memory and does not mention other types of memory.  For now, we
+	 * just re-use that value, but we need to confirm whether that is
+	 * correct or if there are different values depending on the memory
+	 * type.
+	 */
+	.derating = 45,
+};
+
 static int icl_get_bw_info(struct intel_display *display,
 			   const struct dram_info *dram_info,
 			   const struct intel_sa_info *sa)
@@ -812,7 +826,12 @@ void intel_bw_init_hw(struct intel_display *display)
 	if (!HAS_DISPLAY(display))
 		return;
 
-	if (DISPLAY_VERx100(display) >= 3002) {
+	if (DISPLAY_VER(display) >= 35) {
+		if (dram_info->ecc_impacting_de)
+			tgl_get_bw_info(display, dram_info, &xe3p_lpd_ecc_sa_info);
+		else
+			tgl_get_bw_info(display, dram_info, &xe3lpd_sa_info);
+	} else if (DISPLAY_VERx100(display) >= 3002) {
 		tgl_get_bw_info(display, dram_info, &xe3lpd_3002_sa_info);
 	} else if (DISPLAY_VER(display) >= 30) {
 		tgl_get_bw_info(display, dram_info, &xe3lpd_sa_info);

-- 
2.51.0