kernel: revert a faulty upstream commit that was added with the spi-nor/m25p80 backport (fixes #20971)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47664 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 35 insertions, 0 deletions

diff --git a/target/linux/generic/patches-4.1/141-Revert-mtd-spi-nor-disable-protection-for-Winbond-fl.patch b/target/linux/generic/patches-4.1/141-Revert-mtd-spi-nor-disable-protection-for-Winbond-fl.patch
new file mode 100644
index 0000000000..10b43d51bc
--- /dev/null
+++ b/target/linux/generic/patches-4.1/141-Revert-mtd-spi-nor-disable-protection-for-Winbond-fl.patch
@@ -0,0 +1,35 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Thu, 26 Nov 2015 17:03:46 +0100
+Subject: [PATCH] Revert "mtd: spi-nor: disable protection for Winbond flash at
+ startup"
+
+This reverts commit c6fc2171b249e73745c497b578b417a2946f1b2f.
+
+This commit is breaking read access on at least s25fl064k, but also
+possibly other Spansion flash chips.
+
+Any mtd read seems to succeed, but simply returns a zero-filled buffer.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/mtd/spi-nor/spi-nor.c
++++ b/drivers/mtd/spi-nor/spi-nor.c
+@@ -1194,14 +1194,13 @@ int spi_nor_scan(struct spi_nor *nor, co
+ 	mutex_init(&nor->lock);
+ 
+ 	/*
+-	 * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
+-	 * with the software protection bits set
++	 * Atmel, SST and Intel/Numonyx serial nor tend to power
++	 * up with the software protection bits set
+ 	 */
+ 
+ 	if (JEDEC_MFR(info) == SNOR_MFR_ATMEL ||
+ 	    JEDEC_MFR(info) == SNOR_MFR_INTEL ||
+-	    JEDEC_MFR(info) == SNOR_MFR_SST ||
+-	    JEDEC_MFR(info) == SNOR_MFR_WINBOND) {
++	    JEDEC_MFR(info) == SNOR_MFR_SST) {
+ 		write_enable(nor);
+ 		write_sr(nor, 0);
+ 	}