[PATCH v6 0/3] mtd: nand: gpmi: add proper raw access support

Huang Shijie shijie.huang at intel.com
Mon Dec 1 16:47:43 PST 2014


On Mon, Dec 01, 2014 at 09:58:58AM +0100, Boris Brezillon wrote:
> Hi Brian,
> 
> On Mon, 1 Dec 2014 00:47:09 -0800
> Brian Norris <computersforpeace at gmail.com> wrote:
> 
> > On Sun, Nov 30, 2014 at 07:10:27PM +0100, Boris Brezillon wrote:
> > > Hello,
> > > 
> > > This series provides an implementation for raw accesses taking care of
> > > hidding the specific layout used by the GPMI controller.
> > > 
> > > Best Regards,
> > > 
> > > Boris
> > > 
> > > Changes since v5:
> > >  - rename gpmi_move_bits into gpmi_copy_bits
> > > 
> > > Changes since v4:
> > >  - fixed a few corner cases in gpmi_move_bits (tested it with:
> > >    https://github.com/bbrezillon/gpmi-move-bits-test/blob/master/gpmi-move-bits-test.c)
> > >  - add documentation and comments for the new gpmi functions
> > > 
> > > Changes since v3:
> > >  - add comments to the gpmi_move_bits function
> > >  - extend raw read/write documentation
> > >  - move last part of the raw_page_read function into a conditional block
> > > 
> > > Changes since v2:
> > >  - fixed a bug in gpmi_move_bits
> > >  - add a raw_buffer field to be used when using raw access methods
> > >    (experienced memory corruptions when directly using page_buffer_virt
> > >    buffer)
> > >  - add raw OOB access functions
> > 
> > Applied the series. Thanks!
> > 
> > Out of curiosity, what tests does gpmi-nand.c now pass/fail?
> 
> The oobtest is still failing. I started to debug it, but didn't have
> enough time to make it work.
> 
> The nandbiterrs test is working, though I didn't manage to make the
> incremental test fail (writing the same pattern 10000 times without
> erasing the block between each write does not generate any bit flips) on
> my SLC NAND: MT29F2G08ABAEAH4.
> Can someone with another SLC NAND chip try it ?
> 
> > 
> > Also, is it time to yank / fixup some of these comments from
> > gpmi-nand.c?
> 
> I was asking myself the same question...
> 
> > 
> >  ...
> >  * FIXME: The following paragraph is incorrect, now that there exist
> >  * ecc.read_oob_raw and ecc.write_oob_raw functions.
> >  *
> >  * Since MTD assumes the OOB is not covered by ECC, there is no pair of
> >  * ECC-based/raw functions for reading or or writing the OOB. The fact that the
> >  * caller wants an ECC-based or raw view of the page is not propagated down to
> >  * this driver.
> >  */
> 
> I guess we can remove them.
> Huang can you confirm that the raw access functions introduced in this
> series are covering what's described here ?
I think we can remove these comments now.

thanks
Huang Shijie



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