mtd: nand: pxa3xx: Fix READOOB implementation

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=fee4380f368e84ed216b62ccd2fbc4126f2bf40b
Commit:     fee4380f368e84ed216b62ccd2fbc4126f2bf40b
Parent:     30a7acd573899fd8b8ac39236eff6468b195ac7d
Author:     Boris Brezillon <boris.brezillon at free-electrons.com>
AuthorDate: Mon Dec 18 11:32:45 2017 +0100
Committer:  Richard Weinberger <richard at nod.at>
CommitDate: Sat Jan 6 23:06:58 2018 +0100

    mtd: nand: pxa3xx: Fix READOOB implementation
    
    In the current driver, OOB bytes are accessed in raw mode, and when a
    page access is done with NDCR_SPARE_EN set and NDCR_ECC_EN cleared, the
    driver must read the whole spare area (64 bytes in case of a 2k page,
    16 bytes for a 512 page). The driver was only reading the free OOB
    bytes, which was leaving some unread data in the FIFO and was somehow
    leading to a timeout.
    
    We could patch the driver to read ->spare_size + ->ecc_size instead of
    just ->spare_size when READOOB is requested, but we'd better make
    in-band and OOB accesses consistent.
    Since the driver is always accessing in-band data in non-raw mode (with
    the ECC engine enabled), we should also access OOB data in this mode.
    That's particularly useful when using the BCH engine because in this
    mode the free OOB bytes are also ECC protected.
    
    Fixes: 43bcfd2bb24a ("mtd: nand: pxa3xx: Add driver-specific ECC BCH support")
    Cc: stable at vger.kernel.org
    Reported-by: Sean Nyekjær <sean.nyekjaer at prevas.dk>
    Tested-by: Willy Tarreau <w at 1wt.eu>
    Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
    Acked-by: Ezequiel Garcia <ezequiel at vanguardiasur.com.ar>
    Tested-by: Sean Nyekjaer <sean.nyekjaer at prevas.dk>
    Acked-by: Robert Jarzmik <robert.jarzmik at free.fr>
    Signed-off-by: Richard Weinberger <richard at nod.at>
---
 drivers/mtd/nand/pxa3xx_nand.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 90b9a9ccbe60..9285f60e5783 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -963,6 +963,7 @@ static void prepare_start_command(struct pxa3xx_nand_info *info, int command)
 
 	switch (command) {
 	case NAND_CMD_READ0:
+	case NAND_CMD_READOOB:
 	case NAND_CMD_PAGEPROG:
 		info->use_ecc = 1;
 		break;