On Thu, Jul 20, 2023 at 10:24:18AM +0200, Hannes Reinecke wrote:
> On 7/20/23 00:03, Daniel Golle wrote:
> > Add new flag to destinguish block devices which should not act as an
> > NVMEM provider, such as for example an emulated block device on top of
> > an MTD partition which already acts as an NVMEM provider itself.
> >
> > Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> > ---
> > include/linux/blkdev.h | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> > index 2f5371b8482c0..e853d1815be15 100644
> > --- a/include/linux/blkdev.h
> > +++ b/include/linux/blkdev.h
> > @@ -80,11 +80,14 @@ struct partition_meta_info {
> > * ``GENHD_FL_NO_PART``: partition support is disabled. The kernel will not
> > * scan for partitions from add_disk, and users can't add partitions manually.
> > *
> > + * ``GENHD_FL_NO_NVMEM``: NVMEM emulation is disabled. The kernel will not
> > + * emulate an NVMEM device on top of this disk.
> > */
> > enum {
> > GENHD_FL_REMOVABLE = 1 << 0,
> > GENHD_FL_HIDDEN = 1 << 1,
> > GENHD_FL_NO_PART = 1 << 2,
> > + GENHD_FL_NO_NVMEM = 1 << 3,
> > };
> > enum {
> Please reverse this flag. Most of the devices will not have an NVMEM
> partition, and we shouldn't require each and every driver to tag their
> devices.
> So please use GENHD_FL_NVMEM and only set this flag on devices which really
> have an NVMEM partition.
The idea here was to exclude all those devices which already implement
an NVMEM provider on a lower layer themselves, such as MTD.
In this cases it would be ambigous if the OF node represents the
NVMEM device registered by the MTD framework or if blk-nvmem should be
used.
In all other cases device tree can unambigously indicate whether a
block device should serve as NVMEM provider (and right, most of them
never will).
However, reversing the logic seems fine just as well.
