Re: [PATCH v8 08/15] drm/imx: dc: Add DPR channel support

[Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>]

On Fri, Oct 30, 2026 at 05:54:32PM +0800, Liu Ying wrote:
> Display Prefetch Resolve Channel(DPRC) is a part of a prefetch engine.
> It fetches display data, transforms it to linear format and stores it
> to DPRC's RTRAM.  PRG, as the other part of a prefetch engine, acts as
> a gasket between the RTRAM controller and a FetchUnit.  Add a platform
> driver to support the DPRC.
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Acked-by: Maxime Ripard <mripard@kernel.org>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v8:
> - Check device_link_add()'s return value and bail out if needed.
>   (Sashiko AI bot)
> - Mask IRQ_DPR_CRTL_DONE irq and synchronize wrap_irq in
>   dc_dprc_disable_repeat_en() to avoid a race condition.  (Sashiko AI bot)
> - Call devm_pm_runtime_enable() before devm_request_irq() to avoid reading
>   dprc->reg in dc_dprc_wrap_irq_handler while dprc->clks are disabled, since
>   another device sharing wrap_irq could raise an interrupt during probe.
>   (Sashiko AI bot)
> - Drop an unused header file.  (Laurentiu)
> - Use dev_err_probe() to handle errors returned from several function calls.
>   (Laurentiu)
> 
> v7:
> - Collect Maxime's A-b tag.
> - Fix dc_dprc_regmap_write_ranges[].  (Sashiko AI bot)
> - Fix dc_dprc_wrap_irq_handler() return value.  (Sashiko AI bot)
> - Check runtime PM status in dc_dprc_wrap_irq_handler().  (Sashiko AI bot)
> - Fix DPU_DRPC_MAX_STRIDE macro.  (Sashiko AI bot)
> - Support deferral probe if platform_get_irq_byname() fails.  (Sashiko AI bot)
> - Avoid dangling prg->dprc by calling dc_prg_set_dprc() properly.
>   (Sashiko AI bot)
> - Add dc_dprc_get() helper for consumer device to get DPRC properly.
> - Set use_raw_spinlock flag in regmap configuration to avoid a potential
>   hard lockup because dc_dprc_disable_repeat_en() is supposed to be called
>   with local irq and preempt disabled.
> 
> v6:
> - Include "dc-drv.h" to avoid build warning with C=1.
> 
> v3:
> - Call dc_dprc_enable() only when start == true.  (Frank)
> - Collect Frank's R-b tag.
> 
> v2:
> - Manage clocks with bulk interfaces.  (Frank)
> - Sort variables in probe function in reverse Christmas tree fashion.  (Frank)
> ---
>  drivers/gpu/drm/imx/dc/Kconfig   |   1 +
>  drivers/gpu/drm/imx/dc/Makefile  |   6 +-
>  drivers/gpu/drm/imx/dc/dc-dprc.c | 534 +++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/imx/dc/dc-dprc.h |  37 +++
>  drivers/gpu/drm/imx/dc/dc-drv.c  |   1 +
>  drivers/gpu/drm/imx/dc/dc-drv.h  |   1 +
>  drivers/gpu/drm/imx/dc/dc-prg.c  |  12 +
>  drivers/gpu/drm/imx/dc/dc-prg.h  |   4 +
>  8 files changed, 593 insertions(+), 3 deletions(-)
> 

[...]

> diff --git a/drivers/gpu/drm/imx/dc/dc-dprc.c b/drivers/gpu/drm/imx/dc/dc-dprc.c
> new file mode 100644
> index 000000000000..29188fa72a32
> --- /dev/null
> +++ b/drivers/gpu/drm/imx/dc/dc-dprc.c

[...]

> +bool dc_dprc_rtram_width_supported(struct dc_dprc *dprc, unsigned int width)

In your reply to my v7 comment, you also said that this function uses the
'dprc' argument in later commits. FWIW, I couldn't find those commits in this
series that do.  So, you could get rid of it too.

Otherwise:
Reviewed-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>

> +{
> +	return width <= DPU_DPRC_MAX_RTRAM_WIDTH;
> +}

[...]

-- 
Thanks,
Laurentiu