[PATCH RFT 03/14] drm/msm/adreno: Offset the HBB value by 13

[Connor Abbott]

On Thu, May 8, 2025 at 2:13 PM Konrad Dybcio <konradybcio at kernel.org> wrote:
>
> From: Konrad Dybcio <konrad.dybcio at oss.qualcomm.com>
>
> The value the UBWC hardware expects is 13 less than the actual value.
> To make it easier to migrate to a common UBWC configuration table,
> defer that logic to the data source (which is currently a number of
> if-else statements with assignments in case of this driver).

Don't break the value exposed to userspace!

Connor

>
> Signed-off-by: Konrad Dybcio <konrad.dybcio at oss.qualcomm.com>
> ---
>  drivers/gpu/drm/msm/adreno/a5xx_gpu.c |  7 +++----
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 30 ++++++++++++------------------
>  2 files changed, 15 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> index 650e5bac225f372e819130b891f1d020b464f17f..67331a7ee750c0d9eeeead9440e5d08b1a09c878 100644
> --- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> @@ -833,8 +833,7 @@ static int a5xx_hw_init(struct msm_gpu *gpu)
>
>         gpu_write(gpu, REG_A5XX_RBBM_AHB_CNTL2, 0x0000003F);
>
> -       BUG_ON(adreno_gpu->ubwc_config.highest_bank_bit < 13);
> -       hbb = adreno_gpu->ubwc_config.highest_bank_bit - 13;
> +       hbb = adreno_gpu->ubwc_config.highest_bank_bit;
>
>         gpu_write(gpu, REG_A5XX_TPL1_MODE_CNTL, hbb << 7);
>         gpu_write(gpu, REG_A5XX_RB_MODE_CNTL, hbb << 1);
> @@ -1792,9 +1791,9 @@ struct msm_gpu *a5xx_gpu_init(struct drm_device *dev)
>
>         /* Set the highest bank bit */
>         if (adreno_is_a540(adreno_gpu) || adreno_is_a530(adreno_gpu))
> -               adreno_gpu->ubwc_config.highest_bank_bit = 15;
> +               adreno_gpu->ubwc_config.highest_bank_bit = 2;
>         else
> -               adreno_gpu->ubwc_config.highest_bank_bit = 14;
> +               adreno_gpu->ubwc_config.highest_bank_bit = 1;
>
>         /* a5xx only supports UBWC 1.0, these are not configurable */
>         adreno_gpu->ubwc_config.macrotile_mode = 0;
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index bf3758f010f4079aa86f9c658b52a70acf10b488..b161b5cd991fc645dfcd69754b82be9691775ffe 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -592,32 +592,32 @@ static void a6xx_calc_ubwc_config(struct adreno_gpu *gpu)
>         gpu->ubwc_config.min_acc_len = 0;
>         gpu->ubwc_config.ubwc_swizzle = 0x6;
>         gpu->ubwc_config.macrotile_mode = 0;
> -       gpu->ubwc_config.highest_bank_bit = 15;
> +       gpu->ubwc_config.highest_bank_bit = 2;
>
>         if (adreno_is_a610(gpu)) {
> -               gpu->ubwc_config.highest_bank_bit = 13;
> +               gpu->ubwc_config.highest_bank_bit = 0;
>                 gpu->ubwc_config.min_acc_len = 1;
>                 gpu->ubwc_config.ubwc_swizzle = 0x7;
>         }
>
>         if (adreno_is_a618(gpu))
> -               gpu->ubwc_config.highest_bank_bit = 14;
> +               gpu->ubwc_config.highest_bank_bit = 1;
>
>         if (adreno_is_a619(gpu))
>                 /* TODO: Should be 14 but causes corruption at e.g. 1920x1200 on DP */
> -               gpu->ubwc_config.highest_bank_bit = 13;
> +               gpu->ubwc_config.highest_bank_bit = 0;
>
>         if (adreno_is_a619_holi(gpu))
> -               gpu->ubwc_config.highest_bank_bit = 13;
> +               gpu->ubwc_config.highest_bank_bit = 0;
>
>         if (adreno_is_a621(gpu)) {
> -               gpu->ubwc_config.highest_bank_bit = 13;
> +               gpu->ubwc_config.highest_bank_bit = 0;
>                 gpu->ubwc_config.amsbc = 1;
>                 gpu->ubwc_config.uavflagprd_inv = 2;
>         }
>
>         if (adreno_is_a623(gpu)) {
> -               gpu->ubwc_config.highest_bank_bit = 16;
> +               gpu->ubwc_config.highest_bank_bit = 3;
>                 gpu->ubwc_config.amsbc = 1;
>                 gpu->ubwc_config.rgb565_predicator = 1;
>                 gpu->ubwc_config.uavflagprd_inv = 2;
> @@ -636,7 +636,7 @@ static void a6xx_calc_ubwc_config(struct adreno_gpu *gpu)
>             adreno_is_a730(gpu) ||
>             adreno_is_a740_family(gpu)) {
>                 /* TODO: get ddr type from bootloader and use 2 for LPDDR4 */
> -               gpu->ubwc_config.highest_bank_bit = 16;
> +               gpu->ubwc_config.highest_bank_bit = 3;
>                 gpu->ubwc_config.amsbc = 1;
>                 gpu->ubwc_config.rgb565_predicator = 1;
>                 gpu->ubwc_config.uavflagprd_inv = 2;
> @@ -644,7 +644,7 @@ static void a6xx_calc_ubwc_config(struct adreno_gpu *gpu)
>         }
>
>         if (adreno_is_a663(gpu)) {
> -               gpu->ubwc_config.highest_bank_bit = 13;
> +               gpu->ubwc_config.highest_bank_bit = 0;
>                 gpu->ubwc_config.amsbc = 1;
>                 gpu->ubwc_config.rgb565_predicator = 1;
>                 gpu->ubwc_config.uavflagprd_inv = 2;
> @@ -653,14 +653,14 @@ static void a6xx_calc_ubwc_config(struct adreno_gpu *gpu)
>         }
>
>         if (adreno_is_7c3(gpu)) {
> -               gpu->ubwc_config.highest_bank_bit = 14;
> +               gpu->ubwc_config.highest_bank_bit = 1;
>                 gpu->ubwc_config.amsbc = 1;
>                 gpu->ubwc_config.uavflagprd_inv = 2;
>                 gpu->ubwc_config.macrotile_mode = 1;
>         }
>
>         if (adreno_is_a702(gpu)) {
> -               gpu->ubwc_config.highest_bank_bit = 14;
> +               gpu->ubwc_config.highest_bank_bit = 1;
>                 gpu->ubwc_config.min_acc_len = 1;
>         }
>  }
> @@ -668,13 +668,7 @@ static void a6xx_calc_ubwc_config(struct adreno_gpu *gpu)
>  static void a6xx_set_ubwc_config(struct msm_gpu *gpu)
>  {
>         struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> -       /*
> -        * We subtract 13 from the highest bank bit (13 is the minimum value
> -        * allowed by hw) and write the lowest two bits of the remaining value
> -        * as hbb_lo and the one above it as hbb_hi to the hardware.
> -        */
> -       BUG_ON(adreno_gpu->ubwc_config.highest_bank_bit < 13);
> -       u32 hbb = adreno_gpu->ubwc_config.highest_bank_bit - 13;
> +       u32 hbb = adreno_gpu->ubwc_config.highest_bank_bit;
>         u32 hbb_hi = hbb >> 2;
>         u32 hbb_lo = hbb & 3;
>         u32 ubwc_mode = adreno_gpu->ubwc_config.ubwc_swizzle & 1;
>
> --
> 2.49.0
>