Re: [PATCH] PCI/PME: Replace RMW of Root Status register with direct write

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

[-- Attachment #1: Type: text/plain, Size: 1098 bytes --]

On Sun, 26 Oct 2025, Lukas Wunner wrote:

> As of PCIe r7.0, the Root Status register contains a single writeable bit
> (PME Status, type RW1C) and otherwise just read-only bits and RsvdZ bits
> (which software must write as zero, PCIe r7.0 sec 7.4).
> 
> Thus, when clearing the PME Status bit, there's no need to perform a
> read-modify-write of the register.  Instead, the bit can be written
> directly.
> 
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> ---
>  drivers/pci/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index b14dd064006c..411a0b88841e 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2285,7 +2285,7 @@ void pcie_clear_device_status(struct pci_dev *dev)
>   */
>  void pcie_clear_root_pme_status(struct pci_dev *dev)
>  {
> -	pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
> +	pcie_capability_write_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
>  }
>  
>  /**
> 

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

-- 
 i.