Re: [PATCH 3/9] drm/tegra: Explicitly specify PMC instance to use

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Resource Acquisition Order / Hardware Delay Inefficiency in tegra_dc_probe()
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commit dfa12a000e50667e2028e62a77d85dddde33c3e6
Author: Thierry Reding <treding@nvidia.com>

drm/tegra: Explicitly specify PMC instance to use

Currently the kernel relies on a global variable to reference the PMC
context. Use an explicit lookup for the PMC and pass that to the public
PMC APIs.

> diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
> index 06370b7e0e567..e6099f5aced7a 100644
> --- a/drivers/gpu/drm/tegra/dc.c
> +++ b/drivers/gpu/drm/tegra/dc.c
> @@ -3231,12 +3232,17 @@ static int tegra_dc_probe(struct platform_device *pdev)
>  	clk_disable_unprepare(dc->clk);
>  
>  	if (dc->soc->has_powergate) {
> +		dc->pmc = devm_tegra_pmc_get(dc->dev);
> +		if (IS_ERR(dc->pmc))
> +			return dev_err_probe(dc->dev, PTR_ERR(dc->pmc),
> +					     "failed to get PMC\n");
> +

Would it be better to move devm_tegra_pmc_get() earlier in tegra_dc_probe()
before the hardware operations and delays?

Looking at tegra_dc_probe(), this lookup happens after clk_prepare_enable(),
reset_control_assert(), and multiple usleep_range(2000, 4000) delays.

If devm_tegra_pmc_get() returns -EPROBE_DEFER, the probe aborts after executing
4-8ms of synchronous hardware delays.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260506-pmc-v1-0-a6de5da7216b@nvidia.com?part=3