mtd: nand: brcmnand: Disable prefetch by default

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@gmail.com>
Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller")
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index d9fab22..1a4a790 100644 (file)
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -2193,16 +2193,9 @@ static int brcmnand_setup_dev(struct brcmnand_host *host)
        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;