On Mon, 8 Jan 2018 15:06:13 -0500 Kamal Dasu kdasu.kdev@gmail.com wrote:

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 Cc: stable@vger.kernel.org

Fixes:????

---

drivers/mtd/nand/brcmnand/brcmnand.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c index dd56a67..2a978d9 100644 --- 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;