drm/i915/bw: Do not consider tile4 as tileY

For the purposes of memory bandwidth calculations tile4
should not be considered the same as tileY. Make it so.

This should not actually change anything as the affected
code only applies to pre-MTL integrated GPUs, which don't
have tile4.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260522200346.17377-11-ville.syrjala@linux.intel.com
Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>

1 files changed, 16 insertions, 13 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index d0fb4ce91401..dc5a5b639d87 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -240,10 +240,15 @@ intel_read_qgv_point_info(struct intel_display *display,
 		return icl_pcode_read_qgv_point_info(display, sp, point);
 }
 
+static bool is_y_tile(struct intel_display *display)
+{
+	/* assume Y tile may be used if supported */
+	return !HAS_4TILE(display);
+}
+
 static int icl_get_qgv_points(struct intel_display *display,
 			      const struct dram_info *dram_info,
-			      struct intel_qgv_info *qi,
-			      bool is_y_tile)
+			      struct intel_qgv_info *qi)
 {
 	int i, ret;
 
@@ -282,16 +287,16 @@ static int icl_get_qgv_points(struct intel_display *display,
 	} else if (DISPLAY_VER(display) >= 12) {
 		switch (dram_info->type) {
 		case INTEL_DRAM_DDR4:
-			qi->t_bl = is_y_tile ? 8 : 4;
+			qi->t_bl = is_y_tile(display) ? 8 : 4;
 			qi->max_numchannels = 2;
 			qi->channel_width = 64;
-			qi->deinterleave = is_y_tile ? 1 : 2;
+			qi->deinterleave = is_y_tile(display) ? 1 : 2;
 			break;
 		case INTEL_DRAM_DDR5:
-			qi->t_bl = is_y_tile ? 16 : 8;
+			qi->t_bl = is_y_tile(display) ? 16 : 8;
 			qi->max_numchannels = 4;
 			qi->channel_width = 32;
-			qi->deinterleave = is_y_tile ? 1 : 2;
+			qi->deinterleave = is_y_tile(display) ? 1 : 2;
 			break;
 		case INTEL_DRAM_LPDDR4:
 			if (display->platform.rocketlake) {
@@ -306,7 +311,7 @@ static int icl_get_qgv_points(struct intel_display *display,
 			qi->t_bl = 16;
 			qi->max_numchannels = 8;
 			qi->channel_width = 16;
-			qi->deinterleave = is_y_tile ? 2 : 4;
+			qi->deinterleave = is_y_tile(display) ? 2 : 4;
 			break;
 		default:
 			qi->t_bl = 16;
@@ -512,7 +517,6 @@ static int icl_get_bw_info(struct intel_display *display,
 			   const struct intel_display_bw_params *display_bw_params)
 {
 	struct intel_qgv_info qi = {};
-	bool is_y_tile = true; /* assume y tile may be used */
 	int num_channels = max_t(u8, 1, dram_info->num_channels);
 	int ipqdepth, ipqdepthpch = 16;
 	int dclk_max;
@@ -520,7 +524,7 @@ static int icl_get_bw_info(struct intel_display *display,
 	int num_groups = ARRAY_SIZE(display->bw.max);
 	int i, ret;
 
-	ret = icl_get_qgv_points(display, dram_info, &qi, is_y_tile);
+	ret = icl_get_qgv_points(display, dram_info, &qi);
 	if (ret) {
 		drm_dbg_kms(display->drm,
 			    "Failed to get memory subsystem information, ignoring bandwidth limits");
@@ -530,7 +534,7 @@ static int icl_get_bw_info(struct intel_display *display,
 	dclk_max = icl_sagv_max_dclk(&qi);
 	maxdebw = min(soc_bw_params->deprogbwlimit * 1000, dclk_max * 16 * 6 / 10);
 	ipqdepth = min(ipqdepthpch, display_bw_params->displayrtids / num_channels);
-	qi.deinterleave = DIV_ROUND_UP(num_channels, is_y_tile ? 4 : 2);
+	qi.deinterleave = DIV_ROUND_UP(num_channels, is_y_tile(display) ? 4 : 2);
 
 	for (i = 0; i < num_groups; i++) {
 		struct intel_bw_info *bi = &display->bw.max[i];
@@ -589,7 +593,6 @@ static int tgl_get_bw_info(struct intel_display *display,
 			   const struct intel_display_bw_params *display_bw_params)
 {
 	struct intel_qgv_info qi = {};
-	bool is_y_tile = true; /* assume y tile may be used */
 	int num_channels = max_t(u8, 1, dram_info->num_channels);
 	int ipqdepth, ipqdepthpch = 16;
 	int maxdebw, peakbw;
@@ -597,7 +600,7 @@ static int tgl_get_bw_info(struct intel_display *display,
 	int num_groups = ARRAY_SIZE(display->bw.max);
 	int i, ret;
 
-	ret = icl_get_qgv_points(display, dram_info, &qi, is_y_tile);
+	ret = icl_get_qgv_points(display, dram_info, &qi);
 	if (ret) {
 		drm_dbg_kms(display->drm,
 			    "Failed to get memory subsystem information, ignoring bandwidth limits");
@@ -728,7 +731,7 @@ static int xe2_hpd_get_bw_info(struct intel_display *display,
 	int peakbw, maxdebw;
 	int ret, i;
 
-	ret = icl_get_qgv_points(display, dram_info, &qi, true);
+	ret = icl_get_qgv_points(display, dram_info, &qi);
 	if (ret) {
 		drm_dbg_kms(display->drm,
 			    "Failed to get memory subsystem information, ignoring bandwidth limits");