Hi Boris,
On Fri, 11 May 2018 14:44:07 +0200, Boris Brezillon boris.brezillon@bootlin.com wrote:
The ONFI spec clearly says that FAIL bit is only valid for PROGRAM, ERASE and READ-with-on-die-ECC operations, and should be ignored otherwise.
It seems that checking it after sending a SET_FEATURES is a bad idea because a previous READ, PROGRAM or ERASE op may have failed, and depending on the implementation, the FAIL bit is not cleared until a new READ, PROGRAM or ERASE is started.
This leads to ->set_features() returning -EIO while it actually worked, which can sometimes stop a batch of READ/PROGRAM ops.
Note that we only fix the ->exec_op() path here, because some drivers are abusing the NAND_STATUS_FAIL flag in their ->waitfunc() implementation to propagate other kind of errors, like wait-ready-timeout or controller-related errors. Let's not try to fix those drivers since they worked fine so far.
Fixes: 8878b126df76 ("mtd: nand: add ->exec_op() implementation") Cc: stable@vger.kernel.org Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com
So we have no real way to know if a SET_FEATURES actually succeeded. I checked the ONFI spec and could not find anything. A GET_FEATURES will do the trick though (when supported).
Acked-by: Miquel Raynal miquel.raynal@bootlin.com