Re: [PATCH] mtd: spinand: Handle the case where PROGRAM LOAD does not reset the cache

[Miquel Raynal <miquel.raynal@xxxxxxxxxxx>]

Hello,

Boris Brezillon <bbrezillon@xxxxxxxxxx> wrote on Thu, 24 Jan 2019
17:33:57 +0100:

> On Thu, 24 Jan 2019 17:16:37 +0100
> Emil Lenngren <emil.lenngren@xxxxxxxxx> wrote:
> 
> > Hi,
> > 
> > Den tors 24 jan. 2019 kl 16:28 skrev Stefan Roese <sr@xxxxxxx>:  
> > >
> > > On 24.01.19 15:20, Boris Brezillon wrote:    
> > > > Looks like PROGRAM LOAD (AKA write cache) does not necessarily reset
> > > > the cache content to 0xFF (depends on vendor implementation), so we
> > > > must fill the page cache entirely even if we only want to program the
> > > > data portion of the page, otherwise we might corrupt the BBM or user
> > > > data previously programmed in OOB area.
> > > >
> > > > Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs")
> > > > Reported-by: Stefan Roese <sr@xxxxxxx>
> > > > Cc: <stable@xxxxxxxxxxxxxxx>
> > > > Signed-off-by: Boris Brezillon <bbrezillon@xxxxxxxxxx>    
> > >
> > > Works fine (limited testing only yet), so:
> > >
> > > Tested-by: Stefan Roese <sr@xxxxxxx>
> > > Reviewed-by: Stefan Roese <sr@xxxxxxx>
> > >
> > > Thanks,
> > > Stefan
> > >    
> > 
> > Can this quirk be made vendor specific?  
> 
> We can make it vendor specific, as long as it's an opt-in thing. This
> way, the default behavior is the safest one, and only when we know a
> chip does reset the cache content on a PROGRAM LOAD time can we add this
> flag.

I am fine with this approach.


Thanks,
Miquèl

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