On 2/23/2023 5:36 PM, Konrad Dybcio wrote:
> Rename lower_bit to hbb_lo and explain what it signifies.
> Add explanations (wherever possible to other tunables).
>
> Sort the variable definition and assignment alphabetically.
Sorting based on decreasing order of line length is more readable, isn't it?
>
> Port setting min_access_length, ubwc_mode and hbb_hi from downstream.
> Set default values for all of the tunables to zero, as they should be.
>
> Values were validated against downstream and will be fixed up in
> separate commits so as not to make this one even more messy.
>
> A618 remains untouched (left at hw defaults) in this patch.
>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 55 ++++++++++++++++++++++++++++-------
> 1 file changed, 45 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index c5f5d0bb3fdc..bdae341e0a7c 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -786,39 +786,74 @@ static void a6xx_set_cp_protect(struct msm_gpu *gpu)
> static void a6xx_set_ubwc_config(struct msm_gpu *gpu)
> {
> struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> - u32 lower_bit = 2;
> + /* Unknown, introduced with A640/680 */
> u32 amsbc = 0;
> + /*
> + * The Highest Bank Bit value represents the bit of the highest DDR bank.
> + * We then subtract 13 from it (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. The default values (when HBB is
> + * not specified) are 0, 0.
> + */
> + u32 hbb_hi = 0;
> + u32 hbb_lo = 0;
> + /* Whether the minimum access length is 64 bits */
> + u32 min_acc_len = 0;
> + /* Unknown, introduced with A650 family, related to UBWC mode/ver 4 */
> u32 rgb565_predicator = 0;
> + /* Unknown, introduced with A650 family */
> u32 uavflagprd_inv = 0;
> + /* Entirely magic, per-GPU-gen value */
> + u32 ubwc_mode = 0;
>
> /* a618 is using the hw default values */
> if (adreno_is_a618(adreno_gpu))
> return;
>
> - if (adreno_is_a640_family(adreno_gpu))
> + if (adreno_is_a619(adreno_gpu)) {
> + /* HBB = 14 */
> + hbb_lo = 1;
> + }
> +
> + if (adreno_is_a630(adreno_gpu)) {
> + /* HBB = 15 */
> + hbb_lo = 2;
> + }
> +
> + if (adreno_is_a640_family(adreno_gpu)) {
> amsbc = 1;
> + /* HBB = 15 */
> + hbb_lo = 2;
> + }
>
> if (adreno_is_a650(adreno_gpu) || adreno_is_a660(adreno_gpu)) {
> - /* TODO: get ddr type from bootloader and use 2 for LPDDR4 */
> - lower_bit = 3;
> amsbc = 1;
> + /* TODO: get ddr type from bootloader and use 2 for LPDDR4 */
> + /* HBB = 16 */
> + hbb_lo = 3;
> rgb565_predicator = 1;
> uavflagprd_inv = 2;
> }
>
> if (adreno_is_7c3(adreno_gpu)) {
> - lower_bit = 1;
> amsbc = 1;
> + /* HBB is unset in downstream DTS, defaulting to 0 */
This is incorrect. For 7c3 hbb value is 14. So hbb_lo should be 1. FYI, hbb configurations were moved to the driver from DT in recent downstream kernels.
-Akhil.
> rgb565_predicator = 1;
> uavflagprd_inv = 2;
> }
>
> gpu_write(gpu, REG_A6XX_RB_NC_MODE_CNTL,
> - rgb565_predicator << 11 | amsbc << 4 | lower_bit << 1);
> - gpu_write(gpu, REG_A6XX_TPL1_NC_MODE_CNTL, lower_bit << 1);
> - gpu_write(gpu, REG_A6XX_SP_NC_MODE_CNTL,
> - uavflagprd_inv << 4 | lower_bit << 1);
> - gpu_write(gpu, REG_A6XX_UCHE_MODE_CNTL, lower_bit << 21);
> + rgb565_predicator << 11 | hbb_hi << 10 | amsbc << 4 |
> + min_acc_len << 3 | hbb_lo << 1 | ubwc_mode);
> +
> + gpu_write(gpu, REG_A6XX_TPL1_NC_MODE_CNTL, hbb_hi << 4 |
> + min_acc_len << 3 | hbb_lo << 1 | ubwc_mode);
> +
> + gpu_write(gpu, REG_A6XX_SP_NC_MODE_CNTL, hbb_hi << 10 |
> + uavflagprd_inv << 4 | min_acc_len << 3 |
> + hbb_lo << 1 | ubwc_mode);
> +
> + gpu_write(gpu, REG_A6XX_UCHE_MODE_CNTL, min_acc_len << 23 | hbb_lo << 21);
> }
>
> static int a6xx_cp_init(struct msm_gpu *gpu)
>
