target/linux/generic/patches-4.1/141-Revert-mtd-spi-nor-disable-protection-for-Winbond-fl.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Thu, 26 Nov 2015 17:03:46 +0100
   3 Subject: [PATCH] Revert "mtd: spi-nor: disable protection for Winbond flash at
   4  startup"
   5
   6 This reverts commit c6fc2171b249e73745c497b578b417a2946f1b2f.
   7
   8 This commit is breaking read access on at least s25fl064k, but also
   9 possibly other Spansion flash chips.
  10
  11 Any mtd read seems to succeed, but simply returns a zero-filled buffer.
  12
  13 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  14 ---
  15
  16 --- a/drivers/mtd/spi-nor/spi-nor.c
  17 +++ b/drivers/mtd/spi-nor/spi-nor.c
  18 @@ -1194,14 +1194,13 @@ int spi_nor_scan(struct spi_nor *nor, co
  19         mutex_init(&nor->lock);
  20
  21         /*
  22 -        * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
  23 -        * with the software protection bits set
  24 +        * Atmel, SST and Intel/Numonyx serial nor tend to power
  25 +        * up with the software protection bits set
  26          */
  27
  28         if (JEDEC_MFR(info) == SNOR_MFR_ATMEL ||
  29             JEDEC_MFR(info) == SNOR_MFR_INTEL ||
  30 -           JEDEC_MFR(info) == SNOR_MFR_SST ||
  31 -           JEDEC_MFR(info) == SNOR_MFR_WINBOND) {
  32 +           JEDEC_MFR(info) == SNOR_MFR_SST) {
  33                 write_enable(nor);
  34                 write_sr(nor, 0);
  35         }