This is a note to let you know that I've just added the patch titled
mtd: nand: brcmnand: Disable prefetch by default
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mtd-nand-brcmnand-disable-prefetch-by-default.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f953f0f89663c39f08f4baaa8a4a881401b65654 Mon Sep 17 00:00:00 2001
From: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
Date: Mon, 8 Jan 2018 15:36:48 -0500
Subject: mtd: nand: brcmnand: Disable prefetch by default
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
@@ -2193,16 +2193,9 @@ static int brcmnand_setup_dev(struct brc
if (ctrl->nand_version >= 0x0702)
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;
Patches currently in stable-queue which might be from kdasu.kdev@xxxxxxxxx are
queue-4.15/mtd-nand-brcmnand-disable-prefetch-by-default.patch