Re: [RFC PATCH 2/2] mmc: add OpenFirmware bindings for the mmc_spidriver

From: Anton Vorontsov
Date: Mon May 26 2008 - 07:58:50 EST


On Sat, May 24, 2008 at 12:35:27PM +1000, Stephen Rothwell wrote:
> Hi Anton,
>
> On Fri, 23 May 2008 22:28:42 +0400 Anton Vorontsov <avorontsov@xxxxxxxxxxxxx> wrote:
> >
> > +++ b/drivers/mmc/host/of_mmc_spi.c
>
> > +static int of_mmc_spi_probe(struct spi_device *spi)
>
> > + /*
> > + * mmc_spi_probe will use drvdata, so we can't use it. Use node's
> > + * data instead.
> > + */
> > + spi->dev.archdata.of_node->data = oms;
>
> If you delay this assignment, you may not have to clean it up in the
> error path.

No, if I delay it I'll have to clean it up anyway, just a bit later
(after mmc_spi_probe() fail).

> > + ocr_mask = of_get_property(np, "linux,mmc-ocr-mask", &size);
>
> You should really explicitly include linux/of.h to use of_get_property etc

Thanks, will do.

> > +int __devexit of_mmc_spi_remove(struct spi_device *spi)
> > +{
> > + struct of_mmc_spi *oms = spi->dev.archdata.of_node->data;
> > + int ret;
> > +
> > + ret = mmc_spi_remove(spi);
> > + if (ret)
> > + return ret;
>
> Maybe you should do this last so that you don't leak more than necessary
> if mmc_spi_remove fails. (I don't know what state mmc_spi_remove leaves
> stuff in if it fails ...)

If I do this last, then of_mmc_spi_remove() would be not safe to call
multiple times on non-fatal errors (e.g. when mmc_spi_remove() returns
-EBUSY (despite that currently mmc_spi_remove can't fail)).

Also, if I do this last, then there will be a potential use-after-free
in the mmc_spi driver.

> > +static struct spi_driver of_mmc_spi_driver = {
> > + .driver = {
> > + .name = "of_mmc_spi",
> > + .bus = &spi_bus_type,
>
> This is initialised by spi_register_driver().

This was straight copy from the mmc_spi.c. Will fix.

Thanks,

--
Anton Vorontsov
email: cbouatmailru@xxxxxxxxx
irc://irc.freenode.net/bd2
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