drm/msm/a6xx: Resolve the meaning of UBWC_MODE

This bit is set iff the UBWC version is 1.0. That notably does not
include QCM2290's "no UBWC".

This commit is intentionally cross-subsystem to ease review, as the
patchset is intended to be merged together, with a maintainer
consensus.

Reviewed-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Konrad Dybcio <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/660971/
Signed-off-by: Rob Clark <[email protected]>

Author: quic-kdybcio

drivers/gpu/drm/msm/adreno/a6xx_gpu.c

@@ -687,11 +687,11 @@ static void a6xx_set_ubwc_config(struct msm_gpu *gpu)
 	 */
 	BUG_ON(adreno_gpu->ubwc_config.highest_bank_bit < 13);
 	u32 hbb = adreno_gpu->ubwc_config.highest_bank_bit - 13;
+	bool ubwc_mode = qcom_ubwc_get_ubwc_mode(cfg);
 	bool amsbc = cfg->ubwc_enc_version >= UBWC_3_0;
 	u8 uavflagprd_inv = 0;
 	u32 hbb_hi = hbb >> 2;
 	u32 hbb_lo = hbb & 3;
-	u32 ubwc_mode = adreno_gpu->ubwc_config.ubwc_swizzle & 1;
 	u32 level2_swizzling_dis = !(adreno_gpu->ubwc_config.ubwc_swizzle & 2);
 
 	if (adreno_is_a650_family(adreno_gpu) || adreno_is_a7xx(adreno_gpu))

include/linux/soc/qcom/ubwc.h

@@ -62,4 +62,14 @@ static inline const struct qcom_ubwc_cfg_data *qcom_ubwc_config_get_data(void)
 }
 #endif
 
+static inline bool qcom_ubwc_get_ubwc_mode(const struct qcom_ubwc_cfg_data *cfg)
+{
+	bool ret = cfg->ubwc_enc_version == UBWC_1_0;
+
+	if (ret && !(cfg->ubwc_swizzle & BIT(0)))
+		pr_err("UBWC config discrepancy - level 1 swizzling disabled on UBWC 1.0\n");
+
+	return ret;
+}
+
 #endif /* __QCOM_UBWC_H__ */