Re: [PATCH RESEND] wifi: mt76: mt7921e: Set memory space enable in PCI_COMMAND if unset

[Mario Limonciello]

On 4/9/23 19:57, Sean Wang wrote:
> On Mon, Apr 3, 2023 at 6:42 AM Limonciello, Mario
> <Mario.Limonciello@xxxxxxx> wrote:
> > [Public]
> >
> > > On 3/29/2023 18:24, Sean Wang wrote:
> > > > Hi,
> > > >
> > > > On Wed, Mar 29, 2023 at 1:18 PM Mario Limonciello
> > > > <mario.limonciello@xxxxxxx> wrote:
> > > > > When the BIOS has been configured for Fast Boot, systems with mt7921e
> > > > > have non-functional wifi.  Turning on Fast boot caused both bus master
> > > > > enable and memory space enable bits in PCI_COMMAND not to get
> > > configured.
> > > > > The mt7921 driver already sets bus master enable, but explicitly check
> > > > > and set memory access enable as well to fix this problem.
> > > > >
> > > > > Tested-by: Anson Tsao <anson.tsao@xxxxxxx>
> > > > > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> > > > > ---
> > > > > Original patch was submitted ~3 weeks ago with no comments.
> > > > > Link: https://lore.kernel.org/all/20230310170002.200-1-
> > > mario.limonciello@xxxxxxx/
> > > > > ---
> > > > >    drivers/net/wireless/mediatek/mt76/mt7921/pci.c | 6 ++++++
> > > > >    1 file changed, 6 insertions(+)
> > > > >
> > > > > diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> > > b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> > > > > index cb72ded37256..aa1a427b16c2 100644
> > > > > --- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> > > > > +++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> > > > > @@ -263,6 +263,7 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
> > > > >           struct mt76_dev *mdev;
> > > > >           u8 features;
> > > > >           int ret;
> > > > > +       u16 cmd;
> > > > >
> > > > >           ret = pcim_enable_device(pdev);
> > > > >           if (ret)
> > > > > @@ -272,6 +273,11 @@ static int mt7921_pci_probe(struct pci_dev
> > > *pdev,
> > > > >           if (ret)
> > > > >                   return ret;
> > > > >
> > > > > +       pci_read_config_word(pdev, PCI_COMMAND, &cmd);
> > > > > +       if (!(cmd & PCI_COMMAND_MEMORY)) {
> > > > > +               cmd |= PCI_COMMAND_MEMORY;
> > > > > +               pci_write_config_word(pdev, PCI_COMMAND, cmd);
> > > > > +       }
> > > > If PCI_COMMAND_MEMORY is required in any circumstance, then we
> > > don't
> > > > need to add a conditional check and OR it with PCI_COMMAND_MEMORY.
> > > Generally it seemed advantageous to avoid an extra PCI write if it's not
> > > needed.  For example that's how bus mastering works too (see
> > > __pci_set_master).
> > >
> > >
> > > > Also, I will try the patch on another Intel machine to see if it worked.
> > > Thanks.
> > Did you get a chance to try this on an Intel system?
> Hi,
>
> Sorry for the late response. We have tested the related Intel platform
> and it worked fine. You can add the tag from me like
> Acked-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
Thanks!

Felix, Lorenzo, or Ryder can you guys please pick this up?

Thanks,