Re: [PATCH v2 1/4] skd: Prefer pcie_capability_read_word()

[Frederick Lawler]

Damien Le Moal wrote on 11/17/19 7:45 PM:
> On 2019/11/18 9:21, Frederick Lawler wrote:
> > Commit 8c0d3a02c130 ("PCI: Add accessors for PCI Express Capability")
> > added accessors for the PCI Express Capability so that drivers didn't
> > need to be aware of differences between v1 and v2 of the PCI
> > Express Capability.
> >
> > Replace pci_read_config_word() and pci_write_config_word() calls with
> > pcie_capability_read_word() and pcie_capability_write_word().
> >
> > Signed-off-by: Frederick Lawler <fred@xxxxxxxxxxxx>
> > ---
> >   drivers/block/skd_main.c | 8 ++------
> >   1 file changed, 2 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
> > index 51569c199a6c..f25f6ef6b4c7 100644
> > --- a/drivers/block/skd_main.c
> > +++ b/drivers/block/skd_main.c
> > @@ -3134,18 +3134,14 @@ MODULE_DEVICE_TABLE(pci, skd_pci_tbl);
> >   
> >   static char *skd_pci_info(struct skd_device *skdev, char *str)
> >   {
> > -	int pcie_reg;
> > -
> >   	strcpy(str, "PCIe (");
> > -	pcie_reg = pci_find_capability(skdev->pdev, PCI_CAP_ID_EXP);
> >   
> > -	if (pcie_reg) {
> > +	if (pci_is_pcie(skdev->pdev)) {
>
> Maybe return early here ? The reason is that if pci_is_pcie() is false,
> then the string "PCIe (" is not terminated with a closing parenthesis.
> So something like:
>
> 	if (!pci_is_pcie(skdev->pdev)) {
> 		strcat(str, ")");
> 		return str;
> 	}
>
> May be better. Note that the "return str" is also rather pointless since
> it is not used by the caller of skd_pci_info().

I agree, but it might be better to include a note that this is not a 
PCIe device. Reading "PCIe ()" seems weird to me.

> >   
> >   		char lwstr[6];
> >   		uint16_t pcie_lstat, lspeed, lwidth;
> >   
> > -		pcie_reg += 0x12;
> > -		pci_read_config_word(skdev->pdev, pcie_reg, &pcie_lstat);
> > +		pcie_capability_read_word(skdev->pdev, 0x12, &pcie_lstat);
> >   		lspeed = pcie_lstat & (0xF);
> >   		lwidth = (pcie_lstat & 0x3F0) >> 4;
> >   

Thanks,
Frederick Lawler