Re: [PATCH 1/1] mtd/intel-spi: Support cmdline-based partition

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi,

I don't think it is good idea to change PCI device name like that.

Instead the MTD cmdline parser should be teach to handle names like this
properly.

On Fri, Mar 27, 2020 at 08:48:39AM -0700, ron minnich wrote:
> anyone? This is in our internal tree but I'd like to get it upstreamed
> if possible.
> 
> On Wed, Mar 25, 2020 at 10:34 AM ron minnich <rminnich@gmail.com> wrote:
> >
> > Sorry, on that first one, I forgot the checkpatch. This one is clean.
> >
> > thanks
> >
> > On Wed, Mar 25, 2020 at 10:34 AM ron minnich <rminnich@gmail.com> wrote:
> > >
> > > The MTD subsystem can support command-line defined partitions
> > > for one or more MTD devices.
> > >
> > > The format is:
> > >  * mtdparts=<mtddef>[;<mtddef]
> > >  * <mtddef>  := <mtd-id>:<partdef>[,<partdef>]
> > >
> > > The ':' currently separates the id from the partdef.
> > >
> > > The mtdparts can define more than one part, in which case
> > > there will be more than one <mtd-id>:<partdef> component.
> > >
> > > On Intel spi devices, the name is set to the PCI slot name,
> > > e.g. 0000:00:1f.5.  There are two : in the name alone.
> > > Since strchr is used to find the <mtd-id>,
> > > in this case it will return the wrong
> > > result. Using strrchr is not an option, as there may
> > > be more than one mtddef in the argument.
> > >
> > > This change modifies the name attached to the intel spi
> > > device, changing all ':' to '.', e.g. 0000:00:1f.5
> > > becomes 0000.00.1f.5. It also adds command line partition
> > > parsing registration to the intel_spi_probe function.
> > >
> > > Signed-off-by: Ronald G. Minnich <rminnich@google.com>
> > > Change-Id: Ibfa5caba51b8cdd3c41c60b15f8f8c583ded82ff
> > > ---
> > >  drivers/mtd/spi-nor/intel-spi-pci.c | 23 +++++++++++++++++++++++
> > >  drivers/mtd/spi-nor/intel-spi.c     |  5 ++++-
> > >  2 files changed, 27 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/mtd/spi-nor/intel-spi-pci.c
> > > b/drivers/mtd/spi-nor/intel-spi-pci.c
> > > index 81329f680bec..dc608d74e824 100644
> > > --- a/drivers/mtd/spi-nor/intel-spi-pci.c
> > > +++ b/drivers/mtd/spi-nor/intel-spi-pci.c
> > > @@ -24,6 +24,24 @@ static const struct intel_spi_boardinfo cnl_info = {
> > >      .type = INTEL_SPI_CNL,
> > >  };
> > >
> > > +/*
> > > + * PCI names use a ':' as a separator, which conflicts
> > > + * with the mtdparts cmdline parameter. Dup the name and
> > > + * replace : with .
> > > + */
> > > +static int fixname(struct pci_dev *pdev)
> > > +{
> > > +    char *name;
> > > +
> > > +    name = kstrdup(pci_name(pdev), GFP_KERNEL);
> > > +    if (!name)
> > > +        return -ENOMEM;
> > > +    strreplace(name, ':', '.');
> > > +    dev_set_name(&pdev->dev, name);
> > > +    kfree(name);
> > > +    return 0;
> > > +}
> > > +
> > >  static int intel_spi_pci_probe(struct pci_dev *pdev,
> > >                     const struct pci_device_id *id)
> > >  {
> > > @@ -41,6 +59,11 @@ static int intel_spi_pci_probe(struct pci_dev *pdev,
> > >      if (!info)
> > >          return -ENOMEM;
> > >
> > > +    if (fixname(pdev)) {
> > > +        kfree(info);
> > > +        return -ENOMEM;
> > > +    }
> > > +
> > >      /* Try to make the chip read/write */
> > >      pci_read_config_dword(pdev, BCR, &bcr);
> > >      if (!(bcr & BCR_WPD)) {
> > > diff --git a/drivers/mtd/spi-nor/intel-spi.c b/drivers/mtd/spi-nor/intel-spi.c
> > > index 61d2a0ad2131..cb08ee4d2029 100644
> > > --- a/drivers/mtd/spi-nor/intel-spi.c
> > > +++ b/drivers/mtd/spi-nor/intel-spi.c
> > > @@ -894,6 +894,8 @@ static const struct spi_nor_controller_ops
> > > intel_spi_controller_ops = {
> > >      .erase = intel_spi_erase,
> > >  };
> > >
> > > +static const char * const part_probes[] = { "cmdlinepart", NULL };
> > > +
> > >  struct intel_spi *intel_spi_probe(struct device *dev,
> > >      struct resource *mem, const struct intel_spi_boardinfo *info)
> > >  {
> > > @@ -941,7 +943,8 @@ struct intel_spi *intel_spi_probe(struct device *dev,
> > >      if (!ispi->writeable || !writeable)
> > >          ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
> > >
> > > -    ret = mtd_device_register(&ispi->nor.mtd, &part, 1);
> > > +    ret = mtd_device_parse_register(&ispi->nor.mtd, part_probes,
> > > +                    NULL, &part, 1);
> > >
> > >      if (ret)
> > >          return ERR_PTR(ret);
> > >
> > > --
> > > 2.25.1.696.g5e7596f4ac-goog

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