Re: NAND parameter page read fails with bitflip and no column change support

["ada@thorsis.com" <ada@thorsis.com>]

Hello Steven, Miquel,

Am Wed, Apr 10, 2024 at 06:45:58PM +0000 schrieb Steven Seeger:
> >I had reached out to Miquel privately with this issue, only due to the desire to
> >help inform maintainers of the issue. I was too busy at the time to join the list
> >and write up something more formal. Miquel provided a small patch for me
> >that did not work at the time, and then I lost access to the board for a while.
> >Now I have a little time and a board, so I am here to report the issue and make it public.
> 
> I tried the patch from Miquel back in February and it works correctly with 6.6.12
> and my older driver without column change support.
> 
> Here is h is patch for reference:
> 
> --- a/drivers/mtd/nand/raw/nand_base.c
> +++ b/drivers/mtd/nand/raw/nand_base.c
> @@ -2123,7 +2123,7 @@ EXPORT_SYMBOL_GPL(nand_reset_op);
>  int nand_read_data_op(struct nand_chip *chip, void *buf, unsigned int len,
>                       bool force_8bit, bool check_only)
>  {
> -       if (!len || !buf)
> +       if (!len || (!check_only && !buf))
>                 return -EINVAL;
>  
>         if (nand_has_exec_op(chip)) {

Looking at the context aka the whole function nand_read_data_op() this
looks fine.  I had reported the same issue in March, referencing the
same commit 9f820fc0651c ("mtd: rawnand: Check the data only read
pattern only once") you mentioned in your other mail:

Link: https://lore.kernel.org/linux-mtd/20240307-pantry-deceit-78ce20f47899@thorsis.com/

With nand_read_data_op() fixed in nand_onfi_detect() the boolean
`use_datain` is true now instead of false (because
rawnand_check_data_only_read_support() calls that function, too).  So
in nand_onfi_detect() code jumps to nand_read_data_op() in the second
loop run now instead of nand_change_read_column_op() which probably
masks that other problem with mtd->writesize not set mentioned in our
earlier discussion.

Long story short: the diff above in itself seems correct to me.  A
test with that fix applied on our sam9x60 board using
nand_soft_waitrdy instead of RB# gpio successfully gets ONFI param
page 1 with nand_read_data_op() after getting ONFI param page 0 with
nand_read_param_page_op() failed.

You said this is a patch/diff from Miquel.  Miquel do you send this
as a proper patch then, or should someone else?

Greets
Alex

P.S.: still busy with other things, no time yet for proper timing
analysis of our other NAND flash problems with logic analyzer etc.


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