Re: [PATCH] drm/msm/a6xx: set ubwc config for A640 and A650

[Jordan Crouse <jcrouse@codeaurora.org>]

On Mon, May 25, 2020 at 11:25:13PM -0400, Jonathan Marek wrote:
> This is required for A640 and A650 to be able to share UBWC-compressed
> images with other HW such as display, which expect this configuration.

> Signed-off-by: Jonathan Marek <jonathan@marek.ca>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 38 ++++++++++++++++++++++-----
>  1 file changed, 32 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index 6f335ae179c8..aa004a261277 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -289,6 +289,37 @@ static void a6xx_set_hwcg(struct msm_gpu *gpu, bool state)
>  	gpu_write(gpu, REG_A6XX_RBBM_CLOCK_CNTL, state ? 0x8aa8aa02 : 0);
>  }
>  
> +static void a6xx_set_ubwc_config(struct msm_gpu *gpu)
> +{
> +	struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> +	u32 lower_bit = 2;
> +	u32 amsbc = 0;
> +	u32 rgb565_predicator = 0;
> +	u32 uavflagprd_inv = 0;
> +

This hardware design has the amazing ability to make me sad every time I see it.

> +	/* a618 is using the hw default values */
> +	if (adreno_is_a618(adreno_gpu))
> +		return;
> +
I've been a recent convert to the cult of <linux/bitfields.h> and FIELD_PREP()
could help, maybe?

if (adreno_is_a640(adreno_gpu)) {
	rb_ncmode = FIELD_PREP(REG_A6XX_RB_NC_MODE_CNTL_AMSBC, 1);
	rb_ncmode |= FIELD_PREP(REG_A6XX_RB_NC_MODE_CNTL_HBB, 2);

	tpl1_ncmode  = FIELD_PREP(REG_A6XX_TPL1_NC_MODE_HBB, 2);

	sp_ncmode  = FIELD_PREP(REG_A6XX_TPL1_NC_MODE_HBB, 2);

	uchemode  = FIELD_PREP(REG_A6XX_UCHE_MODE_CNTL_HBB, 2);
} else if adreno_is_a650(adreno_gpu)) {
	rb_ncmode = FIELD_PREP(REG_A6XX_RB_NC_MODE_CNTL_AMSBC, 1);
	rb_ncmode |= FIELD_PREP(REG_A6XX_RB_NC_MODE_CNTL_HBB, 3);
	rb_ncmode |= FIELD_PREP(REG_A6XX_RB_NC_MODE_CNTL_RGB565, 1);

	tpl1_ncmode  = FIELD_PREP(REG_A6XX_TPL1_NC_MODE_HBB, 3);

	sp_ncmode  = FIELD_PREP(REG_A6XX_TPL1_NC_MODE_HBB, 3);
	sp_ncmode  |= FIELD_PREP(REG_A6XX_TPL1_NC_MODE_UAVFLAGPRD_INV, 2);

	uchemode  = FIELD_PREP(REG_A6XX_UCHE_MODE_CNTL_HBB, 2);
}

I'm not sure if that is any clearer or not. Perhaps this is a problem for the
next person to add a new target. Regardless the code is programming the
hardware correctly so...

Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>


> +	if (adreno_is_a640(adreno_gpu))
> +		amsbc = 1;
> +
> +	if (adreno_is_a650(adreno_gpu)) {
> +		/* TODO: get ddr type from bootloader and use 2 for LPDDR4 */
> +		lower_bit = 3;
> +		amsbc = 1;
> +		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);
> +}
> +
>  static int a6xx_cp_init(struct msm_gpu *gpu)
>  {
>  	struct msm_ringbuffer *ring = gpu->rb[0];
> @@ -478,12 +509,7 @@ static int a6xx_hw_init(struct msm_gpu *gpu)
>  	/* Select CP0 to always count cycles */
>  	gpu_write(gpu, REG_A6XX_CP_PERFCTR_CP_SEL_0, PERF_CP_ALWAYS_COUNT);
>  
> -	if (adreno_is_a630(adreno_gpu)) {
> -		gpu_write(gpu, REG_A6XX_RB_NC_MODE_CNTL, 2 << 1);
> -		gpu_write(gpu, REG_A6XX_TPL1_NC_MODE_CNTL, 2 << 1);
> -		gpu_write(gpu, REG_A6XX_SP_NC_MODE_CNTL, 2 << 1);
> -		gpu_write(gpu, REG_A6XX_UCHE_MODE_CNTL, 2 << 21);
> -	}
> +	a6xx_set_ubwc_config(gpu);
>  
>  	/* Enable fault detection */
>  	gpu_write(gpu, REG_A6XX_RBBM_INTERFACE_HANG_INT_CNTL,
> -- 
> 2.26.1
> 

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