On Wed, May 17, 2017 at 05:29:11PM +0200, Boris Brezillon wrote: > Hi Chris, > > On Wed, 17 May 2017 17:39:07 +1200 > Chris Packham <chris.pack...@alliedtelesis.co.nz> wrote: > > > Setting the of_node for the mtd device allows the generic mtd code to > > setup the partitions. Additionally we must specify a non-zero erasesize > > for the partitions to be writeable. > > > > Signed-off-by: Chris Packham <chris.pack...@alliedtelesis.co.nz> > > --- > > drivers/mtd/devices/mchp23k256.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/mtd/devices/mchp23k256.c > > b/drivers/mtd/devices/mchp23k256.c > > index 2542f5b8b63f..02c6b9dcbd3e 100644 > > --- a/drivers/mtd/devices/mchp23k256.c > > +++ b/drivers/mtd/devices/mchp23k256.c > > @@ -143,6 +143,7 @@ static int mchp23k256_probe(struct spi_device *spi) > > > > data = dev_get_platdata(&spi->dev); > > > > + mtd_set_of_node(&flash->mtd, spi->dev.of_node); > > flash->mtd.dev.parent = &spi->dev; > > flash->mtd.type = MTD_RAM; > > flash->mtd.flags = MTD_CAP_RAM; > > @@ -151,6 +152,10 @@ static int mchp23k256_probe(struct spi_device *spi) > > flash->mtd._read = mchp23k256_read; > > flash->mtd._write = mchp23k256_write; > > > > + flash->mtd.erasesize = PAGE_SIZE; > > + while (flash->mtd.size & (flash->mtd.erasesize - 1)) > > + flash->mtd.erasesize >>= 1; > > + > > Can we fix allocate_partition() to properly handle the > master->erasesize == 0 case instead of doing that?
Is everything actually ready for the eraseblock size to be 0? That would seem surprising to many applications, I would think. Can you, for instance, even use UBI on such a device? BTW, I feel like this check is a little more natural to do with 'mtd->flags & MTD_NO_ERASE', rather than checking the (apparently meaningless) erasesize. (I realize there's a later version of these patches, but I figured I'd put my comments where the suggestion was brought up.) Brian
