4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
commit f953f0f89663c39f08f4baaa8a4a881401b65654 upstream.
Brcm nand controller prefetch feature needs to be disabled
by default. Enabling affects performance on random reads as
well as dma reads.
Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller")
Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/nand/brcmnand/brcmnand.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -1922,16 +1922,9 @@ static int brcmnand_setup_dev(struct brc
tmp &= ~ACC_CONTROL_PARTIAL_PAGE;
tmp &= ~ACC_CONTROL_RD_ERASED;
tmp &= ~ACC_CONTROL_FAST_PGM_RDIN;
- if (ctrl->features & BRCMNAND_HAS_PREFETCH) {
- /*
- * FIXME: Flash DMA + prefetch may see spurious erased-page ECC
- * errors
- */
- if (has_flash_dma(ctrl))
- tmp &= ~ACC_CONTROL_PREFETCH;
- else
- tmp |= ACC_CONTROL_PREFETCH;
- }
+ if (ctrl->features & BRCMNAND_HAS_PREFETCH)
+ tmp &= ~ACC_CONTROL_PREFETCH;
+
nand_writereg(ctrl, offs, tmp);
return 0;