[PATCH v2 1/2] mtd: rawnand: Fix the nand_read_data_op() early check

[Miquel Raynal]

On Thu, 2024-05-16 at 13:13:19 UTC, Miquel Raynal wrote:
> The nand_read_data_op() operation, which only consists in DATA_IN
> cycles, is sadly not supported by all controllers despite being very
> basic. The core, for some time, supposed all drivers would support
> it. An improvement to this situation for supporting more constrained
> controller added a check to verify if the operation was supported before
> attempting it by running the function with the check_only boolean set
> first, and then possibly falling back to another (possibly slightly less
> optimized) alternative.
> 
> An even newer addition moved that check very early and probe time, in
> order to perform the check only once. The content of the operation was
> not so important, as long as the controller driver would tell whether
> such operation on the NAND bus would be possible or not. In practice, no
> buffer was provided (no fake buffer or whatever) as it is anyway not
> relevant for the "check_only" condition. Unfortunately, early in the
> function, there is an if statement verifying that the input parameters
> are right for normal use, making the early check always unsuccessful.
> 
> Fixes: 9f820fc0651c ("mtd: rawnand: Check the data only read pattern only once")
> Cc: stable at vger.kernel.org
> Reported-by: Alexander Dahl <ada at thorsis.com>
> Closes: https://lore.kernel.org/linux-mtd/20240306-shaky-bunion-d28b65ea97d7@thorsis.com/
> Reported-by: Steven Seeger <steven.seeger at flightsystems.net>
> Closes: https://lore.kernel.org/linux-mtd/DM6PR05MB4506554457CF95191A670BDEF7062@DM6PR05MB4506.namprd05.prod.outlook.com/
> Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
> Reviewed-by: Alexander Dahl <ada at thorsis.com>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/fixes.

Miquel