[Intel-gfx] [PATCH] drm/i915/mtl: Skip doubling channel numbers for LPDDR4/LPDDDR5

[Radhakrishna Sripada]

MTL LPDDR5 reported 16b with 8 channels. Previous platforms
reported 32b with 4 channels and hence needed a mulitplication
by a factor of 2. Skip increasing the channels for MTL.

While at it fix the logic while reading dram info num channels.

Bspec: 64631
Fixes: 825477e77912 ("drm/i915/mtl: Obtain SAGV values from MMIO instead of GT pcode mailbox")
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
---
 drivers/gpu/drm/i915/display/intel_bw.c | 3 ++-
 drivers/gpu/drm/i915/intel_dram.c       | 3 +--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index 4ace026b29bd..7601e1061bca 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -439,7 +439,8 @@ static int tgl_get_bw_info(struct drm_i915_private *dev_priv, const struct intel
 		return ret;
 	}
 
-	if (dram_info->type == INTEL_DRAM_LPDDR4 || dram_info->type == INTEL_DRAM_LPDDR5)
+	if (!IS_METEORLAKE(dev_priv) &&
+	    (dram_info->type == INTEL_DRAM_LPDDR4 || dram_info->type == INTEL_DRAM_LPDDR5))
 		num_channels *= 2;
 
 	qi.deinterleave = qi.deinterleave ? : DIV_ROUND_UP(num_channels, is_y_tile ? 4 : 2);
diff --git a/drivers/gpu/drm/i915/intel_dram.c b/drivers/gpu/drm/i915/intel_dram.c
index 2403ccd52c74..bba8cb6e8ae4 100644
--- a/drivers/gpu/drm/i915/intel_dram.c
+++ b/drivers/gpu/drm/i915/intel_dram.c
@@ -471,8 +471,7 @@ static int xelpdp_get_dram_info(struct drm_i915_private *i915)
 	u32 val = intel_uncore_read(&i915->uncore, MTL_MEM_SS_INFO_GLOBAL);
 	struct dram_info *dram_info = &i915->dram_info;
 
-	val = REG_FIELD_GET(MTL_DDR_TYPE_MASK, val);
-	switch (val) {
+	switch (REG_FIELD_GET(MTL_DDR_TYPE_MASK, val)) {
 	case 0:
 		dram_info->type = INTEL_DRAM_DDR4;
 		break;
-- 
2.34.1