RE: [PATCH 1/2] mtd: spi-nor: add a API to restore the addressing mode

[Z.q. Hou]

Hi Cyrille,

Thanks a lot for your comments!

> -----Original Message-----
> From: Cyrille Pitchen [mailto:cyrille.pitchen@xxxxxxxxxx]
> Sent: 2017å12æ1æ 16:53
> To: Z.q. Hou <zhiqiang.hou@xxxxxxx>; linux-mtd@xxxxxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; computersforpeace@xxxxxxxxx;
> dwmw2@xxxxxxxxxxxxx; boris.brezillon@xxxxxxxxxxxxxxxxxx;
> marek.vasut@xxxxxxxxx; richard@xxxxxx
> Subject: Re: [PATCH 1/2] mtd: spi-nor: add a API to restore the addressing
> mode
> 
> Hi Hou,
> 
> Le 24/11/2017 Ã 11:08, Zhiqiang Hou a Ãcrit :
> > From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> >
> > It's better to restore the addressing mode of the SPI flash whenever
> > remove the driver or reboot the system.
> >
> > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> > ---
> >  drivers/mtd/spi-nor/spi-nor.c | 8 ++++++++
> >  include/linux/mtd/spi-nor.h   | 1 +
> >  2 files changed, 9 insertions(+)
> >
> > diff --git a/drivers/mtd/spi-nor/spi-nor.c
> > b/drivers/mtd/spi-nor/spi-nor.c index bc266f70a15b..801cbe99b059
> > 100644
> > --- a/drivers/mtd/spi-nor/spi-nor.c
> > +++ b/drivers/mtd/spi-nor/spi-nor.c
> > @@ -2713,6 +2713,14 @@ static void spi_nor_resume(struct mtd_info
> *mtd)
> >  		dev_err(dev, "resume() failed\n");
> >  }
> >
> > +void spi_nor_restore_addr_mode(struct spi_nor *nor) {
> > +	if ((nor->addr_width == 4) &&
> > +	    (JEDEC_MFR(nor->info) != SNOR_MFR_SPANSION) &&
> > +	    !(nor->info->flags & SPI_NOR_4B_OPCODES))
> > +		set_4byte(nor, nor->info, 0);
> > +}
> + EXPORT_SYMBOL_GPL(spi_nor_restore_addr_mode);
> 
> Like for spi_nor_scan(), you would need to export the symbol for modules.

Yes, I will add this in next version.

> 
> > +
> >  int spi_nor_scan(struct spi_nor *nor, const char *name,
> >  		 const struct spi_nor_hwcaps *hwcaps)  { diff --git
> > a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index
> > d0c66a0975cf..fe9357da2049 100644
> > --- a/include/linux/mtd/spi-nor.h
> > +++ b/include/linux/mtd/spi-nor.h
> > @@ -398,5 +398,6 @@ struct spi_nor_hwcaps {
> >   */
> >  int spi_nor_scan(struct spi_nor *nor, const char *name,
> >  		 const struct spi_nor_hwcaps *hwcaps);
> > +void spi_nor_restore_addr_mode(struct spi_nor *nor);
> >
> Please add the relevant kernel doc.

Yes, will add comments for this API in next version.

> 
> Best regards,
> 
> Cyrille
> 
> >  #endif
> >

Thanks,
Zhiqiang