Re: [PATCH] mtd: spi-nor: read 6 bytes for the ID

Marek Vasut
2014-06-03T14:28:27Z

On Friday, May 30, 2014 at 02:49:30 AM, Huang Shijie wrote:
> On Thu, May 29, 2014 at 10:58:52PM +0200, Marek Vasut wrote:
> > On Wednesday, May 28, 2014 at 07:22:40 AM, Huang Shijie wrote:
> > [...]
> >
> > > From 7b920141899e4e7249bd23792dc8d5f1558cb7ca Mon Sep 17 00:00:00 2001
> > > From: Huang Shijie <b32955@freescale.com>
> > > Date: Mon, 14 Apr 2014 18:09:34 +0800
> > > Subject: [PATCH v2] mtd: spi-nor: read 6 bytes for the ID
> > >
> > > Currently, we read 5 bytes for ID, but s25fl128s has the same
> > > ext_id(0x4d01) with s25fl129p1. The s25fl128s can support the DDR Quad
> > > read, while s25fl129p1 does not. So we have to distinguish the two NOR
> > > flashs.
> > >
> > > This patch reads out 6 bytes for the ID, and use the 6 bytes ID to
> > > search the right flash_info.
> > >
> > > The detail of the patch is:
> > > [1] change the "ext_id" from u16 to u32.
> > >
> > > We can store two bytes or three bytes with the @ext_id now.
> > >
> > > [2] search the right flash_info with the 6byte ID and the new
> > > @ext_id.
> > >
> > > We use "matched" variable to track the legacy two bytes @ext_id.
> > > If the flash_info's @ext_id is three bytes, we will use the
> > > sixth byte of the ID to check it.
> > >
> > > [3] add the new item to spi_nor_ids for s25fl128s.
> > >
> > > Signed-off-by: Huang Shijie <b32955@freescale.com>
> > > ---
> > >
> > > drivers/mtd/spi-nor/spi-nor.c | 30 +++++++++++++++++++++++++-----
> > > 1 files changed, 25 insertions(+), 5 deletions(-)
> >
> > What exactly changed here please ?
>
> This patch will reset the ext_jedec to the old value if the
> sixth-byte-match fails.
>
> ------------------------------------------------------------
> + /* reset back the ext_jedec */
> + ext_jedec >>= 8;
> ------------------------------------------------------------

Uh oh, I think we're getting deeper and deeper into ad-hoc adjustments :-(

Best regards,
Marek Vasut