Re: [PATCH v3 2/2] mtd: spi-nor: Use 4B opcodes when the NOR advertises both 3B and 4B

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 20/11/2018 13:18:49+0000, Tudor.Ambarus@microchip.com wrote:
> Hi, Alexandre,
> 
> On 11/16/2018 03:42 PM, Alexandre Belloni wrote:
> > On 16/11/2018 11:57:10+0000, Tudor.Ambarus@microchip.com wrote:
> >>
> >>
> >> On 11/09/2018 12:49 PM, Tudor.Ambarus@microchip.com wrote:
> >>>
> >>>
> >>> On 10/31/2018 04:45 PM, Boris Brezillon wrote:
> >>>> When the NOR supports 4 bytes opcodes we should use those instead of
> >>>> switching the flash in 4-bytes mode. This way, we don't have to restore
> >>>> the addressing mode when resetting the board.
> >>>>
> >>>> Reported-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> >>>> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> >>>> Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> >>>> Reviewed-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
> >>>
> >>> Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> >>>
> >>
> >> I propose to stall this patch for a week or so, until we will have a clearer
> >> view on how are defined the flashes that don't have 4B opcodes, but can enter
> >> the 4-Byte mode on command.
> >>
> > 
> > Note that this patch is badly needed for some of our boards. without it,
> > they can't reboot properly. I would very much like to see it enter
> > upstream and be backported sooner than later.
> 
> What flash do the boards use? Does your flash support SFDP 4-Byte Instruction
> table? If yes, the following patch should solve your problem indirectly:
> 

It is a MX25L25635FMI-10G

> https://lore.kernel.org/patchwork/patch/1015036/
> 
> You should also apply the following if you want to test it:
> 
> https://lore.kernel.org/patchwork/patch/1013294/
> 

Applying those two patches only doesn't fix the reboot issue.

spi_nor_parse_4bait() is never called.

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com