mtd: rawnand: Prevent sequential reads with on-die ECC engines

commit a62c4597953fe54c6af04166a5e2872efd0e1490 upstream.

Some devices support sequential reads when using the on-die ECC engines,
some others do not. It is a bit hard to know which ones will break other
than experimentally, so in order to avoid such a difficult and painful
task, let's just pretend all devices should avoid using this
optimization when configured like this.

Cc: stable@vger.kernel.org
Fixes: 003fe4b9545b ("mtd: rawnand: Support for sequential cache reads")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Martin Hundebøll <martin@geanix.com>
Link: https://lore.kernel.org/linux-mtd/20231215123208.516590-4-miquel.raynal@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 0607da5..7610619 100644 (file)
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -5171,6 +5171,14 @@ static void rawnand_late_check_supported_ops(struct nand_chip *chip)
        /* The supported_op fields should not be set by individual drivers */
        WARN_ON_ONCE(chip->controller->supported_op.cont_read);
 
+       /*
+        * Too many devices do not support sequential cached reads with on-die
+        * ECC correction enabled, so in this case refuse to perform the
+        * automation.
+        */
+       if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_ON_DIE)
+               return;
+
        if (!nand_has_exec_op(chip))
                return;