[PATCH 1/2] mtd: rawnand: Constrain even more when continuous reads are enabled

[Miquel Raynal]

On Thu, 2024-03-07 at 11:53:14 UTC, Miquel Raynal wrote:
> As a matter of fact, continuous reads require additional handling at the
> operation level in order for them to work properly. The core helpers do
> have this additional logic now, but any time a controller implements its
> own page helper, this extra logic is "lost". This means we need another
> level of per-controller driver checks to ensure they can leverage
> continuous reads. This is for now unsupported, so in order to ensure
> continuous reads are enabled only when fully using the core page
> helpers, we need to add more initial checks.
> 
> Also, as performance is not relevant during raw accesses, we also
> prevent these from enabling the feature.
> 
> This should solve the issue seen with controllers such as the STM32 FMC2
> when in sequencer mode. In this case, the continuous read feature would
> be enabled but not leveraged, and most importantly not disabled, leading
> to further operations to fail.
> 
> Reported-by: Christophe Kerello <christophe.kerello at foss.st.com>
> Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache reads")
> Cc: stable at vger.kernel.org
> Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
> Tested-by: Christophe Kerello <christophe.kerello at foss.st.com>

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

Miquel