Re: [PATCH v5 1/6] PCI: mediatek-gen3: Add missing reset_control_deassert() for mac_rst in mtk_pcie_en7581_power_up()

[Bjorn Helgaas <helgaas@kernel.org>]

On Sat, Nov 30, 2024 at 12:20:10AM +0100, Lorenzo Bianconi wrote:
> Even if this is not a real issue since Airoha EN7581 SoC does not require
> the mac reset line, add missing reset_control_deassert() for mac reset
> line in mtk_pcie_en7581_power_up() callback.

s/mac/MAC/ in English text since "mac" is an acronym, not a real word

This doesn't really say why we need this patch.

This adds both assert and deassert, so it doesn't really look like
adding a *missing* deassert.

On EN7581, is mac_reset optional or always absent?

If mac_reset is always absent for EN7581, why add this patch at all?
If it's optional, say so.

> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  drivers/pci/controller/pcie-mediatek-gen3.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
> index 64ef8ff71b0357b9bf9ad8484095b7aa60c22271..4d1c797a32c236faf79428eb8a83708e9c4f21d8 100644
> --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> @@ -942,6 +942,9 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie)
>  	 */
>  	mdelay(PCIE_EN7581_RESET_TIME_MS);
>  
> +	/* MAC power on and enable transaction layer clocks */
> +	reset_control_deassert(pcie->mac_reset);
> +
>  	pm_runtime_enable(dev);
>  	pm_runtime_get_sync(dev);
>  
> @@ -976,6 +979,7 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie)
>  err_clk_prepare:
>  	pm_runtime_put_sync(dev);
>  	pm_runtime_disable(dev);
> +	reset_control_assert(pcie->mac_reset);
>  	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
>  err_phy_deassert:
>  	phy_power_off(pcie->phy);
> 
> -- 
> 2.47.0
>