Re: [PATCH] ahci: asm1064: correct count of reported ports

[Niklas Cassel <cassel@kernel.org>]

Hello Serge, Andrey,

On Thu, Feb 08, 2024 at 10:27:11AM +0300, Andrey Melnikov wrote:
> > On 2/7/24 12:58 PM, Andrey Jr. Melnikov wrote:
> >
> > > The ASM1064 SATA host controller always reports wrongly,
> > > that it has 24 ports. But in reality, it only has four ports.
> > >
> > > before:
> > > ahci 0000:04:00.0: SSS flag set, parallel bus scan disabled
> > > ahci 0000:04:00.0: AHCI 0001.0301 32 slots 24 ports 6 Gbps 0xffff0f impl SATA mode
> > > ahci 0000:04:00.0: flags: 64bit ncq sntf stag pm led only pio sxs deso sadm sds apst
> > >
> > > after:
> > > ahci 0000:04:00.0: ASM1064 has only four ports
> > > ahci 0000:04:00.0: forcing port_map 0xffff0f -> 0xf
> > > ahci 0000:04:00.0: SSS flag set, parallel bus scan disabled
> > > ahci 0000:04:00.0: AHCI 0001.0301 32 slots 24 ports 6 Gbps 0xf impl SATA mode
> > > ahci 0000:04:00.0: flags: 64bit ncq sntf stag pm led only pio sxs deso sadm sds apst
> > >
> > >
> > > Signed-off-by: Andrey Jr. Melnikov <temnota.am@gmail.com>
> > >
> > > diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> > > index da2e74fce2d9..ec30d8330d16 100644
> > > --- a/drivers/ata/ahci.c
> > > +++ b/drivers/ata/ahci.c
> > > @@ -671,9 +671,14 @@ MODULE_PARM_DESC(mobile_lpm_policy, "Default LPM policy for mobile chipsets");
> > >  static void ahci_pci_save_initial_config(struct pci_dev *pdev,
> > >                                        struct ahci_host_priv *hpriv)
> > >  {
> > > -     if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA && pdev->device == 0x1166) {
> > > -             dev_info(&pdev->dev, "ASM1166 has only six ports\n");
> > > -             hpriv->saved_port_map = 0x3f;
> > > +     if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA) {
> > > +             if (pdev->device == 0x1166) {
> >
> >    Maybe *switch* instead?
> 
> Ok.
> Can someone explain to me - which method I should use here - override
> portmap via hpriv->saved_port_map or mask it via hpriv->mask_port_map
> ?

Serge, you seem to be the last person to touch this in
commit 88589772e80c ("ata: libahci: Discard redundant force_port_map
parameter"), where you removed force_port_map, so you are already
familiar with this code.

From my quick look, it looks like mask_port_map is used to disable one or
more ports from the port_map.

But do you know if there is a reason why platforms that need to do that
can't just change saved_port map directly?


Kind regards,
Niklas