Subject: Re: [PATCH v7 08/24] wfx: add bus_sdio.c

From: Jérôme Pouiller <[email-masked]>
Date: Tue, 05 Oct 2021 10:14:36 +0200

On Friday 1 October 2021 17:23:16 CEST Ulf Hansson wrote:
> On Thu, 30 Sept 2021 at 19:06, Pali Rohár <[email-masked]> wrote:
> > On Thursday 30 September 2021 18:51:09 Jérôme Pouiller wrote:
> > > On Thursday 30 September 2021 12:07:55 CEST Ulf Hansson wrote:
> > > > On Mon, 20 Sept 2021 at 18:12, Jerome Pouiller
> > > > <[email-masked]> wrote:
> > > > >
> > > > > From: Jérôme Pouiller <[email-masked]>
> > > > >
> > > > > Signed-off-by: Jérôme Pouiller <[email-masked]>
> > > > > ---
> > > > >  drivers/net/wireless/silabs/wfx/bus_sdio.c | 261 +++++++++++++++++++++
> > > > >  1 file changed, 261 insertions(+)
> > > > >  create mode 100644 drivers/net/wireless/silabs/wfx/bus_sdio.c
> > > > >
> > > > > diff --git a/drivers/net/wireless/silabs/wfx/bus_sdio.c b/drivers/net/wireless/silabs/wfx/bus_sdio.c
> > > >
> > > > [...]
> > > >
> > > > > +
> > > > > +static int wfx_sdio_probe(struct sdio_func *func,
> > > > > +                         const struct sdio_device_id *id)
> > > > > +{
> > > > > +       struct device_node *np = func->dev.of_node;
> > > > > +       struct wfx_sdio_priv *bus;
> > > > > +       int ret;
> > > > > +
> > > > > +       if (func->num != 1) {
> > > > > +               dev_err(&func->dev, "SDIO function number is %d while it should always be 1 (unsupported chip?)\n",
> > > > > +                       func->num);
> > > > > +               return -ENODEV;
> > > > > +       }
> > > > > +
> > > > > +       bus = devm_kzalloc(&func->dev, sizeof(*bus), GFP_KERNEL);
> > > > > +       if (!bus)
> > > > > +               return -ENOMEM;
> > > > > +
> > > > > +       if (!np || !of_match_node(wfx_sdio_of_match, np)) {
> > > > > +               dev_warn(&func->dev, "no compatible device found in DT\n");
> > > > > +               return -ENODEV;
> > > > > +       }
> > > > > +
> > > > > +       bus->func = func;
> > > > > +       bus->of_irq = irq_of_parse_and_map(np, 0);
> > > > > +       sdio_set_drvdata(func, bus);
> > > > > +       func->card->quirks |= MMC_QUIRK_LENIENT_FN0 |
> > > > > +                             MMC_QUIRK_BLKSZ_FOR_BYTE_MODE |
> > > > > +                             MMC_QUIRK_BROKEN_BYTE_MODE_512;
> > > >
> > > > I would rather see that you add an SDIO_FIXUP for the SDIO card, to
> > > > the sdio_fixup_methods[], in drivers/mmc/core/quirks.h, instead of
> > > > this.
> > >
> > > In the current patch, these quirks are applied only if the device appears
> > > in the device tree (see the condition above). If I implement them in
> > > drivers/mmc/core/quirks.h they will be applied as soon as the device is
> > > detected. Is it what we want?
> > >
> > > Note: we already have had a discussion about the strange VID/PID declared
> > > by this device:
> > >   https://www.spinics.net/lists/netdev/msg692577.html
> >
> > Yes, vendor id 0x0000 is invalid per SDIO spec. So based on this vendor
> > id, it is not possible to write any quirk in mmc/sdio generic code.
> >
> > Ulf, but maybe it could be possible to write quirk based on OF
> > compatible string?
> 
> Yes, that would be better in my opinion.
> 
> We already have DT bindings to describe embedded SDIO cards (a subnode
> to the mmc controller node), so we should be able to extend that I
> think.

So, this feature does not yet exist? Do you consider it is a blocker for
the current patch?

To be honest, I don't really want to take over this change in mmc/core.

-- 
Jérôme Pouiller