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

From: Jérôme Pouiller <[email-masked]>
Date: Thu, 30 Sep 2021 18:51:09 +0200

Hello Ulf,

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

[...]
> > +
> > +static const struct sdio_device_id wfx_sdio_ids[] = {
> > +       { SDIO_DEVICE(SDIO_VENDOR_ID_SILABS, SDIO_DEVICE_ID_SILABS_WF200) },
> > +       { },
> > +};
> > +MODULE_DEVICE_TABLE(sdio, wfx_sdio_ids);
> > +
> > +struct sdio_driver wfx_sdio_driver = {
> > +       .name = "wfx-sdio",
> > +       .id_table = wfx_sdio_ids,
> > +       .probe = wfx_sdio_probe,
> > +       .remove = wfx_sdio_remove,
> > +       .drv = {
> > +               .owner = THIS_MODULE,
> > +               .of_match_table = wfx_sdio_of_match,
> 
> Is there no power management? Or do you intend to add that on top?

It seems we already have had this discussion:

  https://lore.kernel.org/netdev/CAPDyKFqJf=vUqpQg3suDCadKrFTkQWFTY_qp=+yDK=[email-masked]/#r

In this thread, Kalle said:
> Many mac80211 drivers do so that the device is powered off during
> interface down (ifconfig wlan0 down), and as mac80211 does interface
> down automatically during suspend, suspend then works without extra
> handlers.

-- 
Jérôme Pouiller