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-rw-r--r--target/linux/generic/pending-5.4/481-mtd-spi-nor-rework-broken-flash-reset-support.patch167
1 files changed, 167 insertions, 0 deletions
diff --git a/target/linux/generic/pending-5.4/481-mtd-spi-nor-rework-broken-flash-reset-support.patch b/target/linux/generic/pending-5.4/481-mtd-spi-nor-rework-broken-flash-reset-support.patch
new file mode 100644
index 0000000000..b2f73a5cbd
--- /dev/null
+++ b/target/linux/generic/pending-5.4/481-mtd-spi-nor-rework-broken-flash-reset-support.patch
@@ -0,0 +1,167 @@
+From ea92cbb50a78404e29de2cc3999a240615ffb1c8 Mon Sep 17 00:00:00 2001
+From: Chuanhong Guo <gch981213@gmail.com>
+Date: Mon, 6 Apr 2020 17:58:48 +0800
+Subject: [PATCH] mtd: spi-nor: rework broken-flash-reset support
+
+Instead of resetting flash to 3B address on remove hook, this
+implementation only enters 4B mode when needed, which prevents
+more unexpected reboot stuck. This implementation makes it only
+break when a kernel panic happens during flash operation on 16M+
+areas.
+*OpenWrt only*: silent broken-flash-reset warning. We are not dealing
+with vendors and it's unpleasant for users to se that unnecessary
+and long WARN_ON print.
+
+Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
+---
+ drivers/mtd/spi-nor/spi-nor.c | 52 +++++++++++++++++++++++++++++++++--
+ 1 file changed, 49 insertions(+), 3 deletions(-)
+
+--- a/drivers/mtd/spi-nor/spi-nor.c
++++ b/drivers/mtd/spi-nor/spi-nor.c
+@@ -616,6 +616,22 @@ static void spi_nor_set_4byte_opcodes(st
+ }
+ }
+
++static int spi_nor_check_set_addr_width(struct spi_nor *nor, loff_t addr)
++{
++ u8 addr_width;
++
++ if ((nor->flags & (SNOR_F_4B_OPCODES | SNOR_F_BROKEN_RESET)) !=
++ SNOR_F_BROKEN_RESET)
++ return 0;
++
++ addr_width = addr & 0xff000000 ? 4 : 3;
++ if (nor->addr_width == addr_width)
++ return 0;
++
++ nor->addr_width = addr_width;
++ return nor->params.set_4byte(nor, addr_width == 4);
++}
++
+ static int macronix_set_4byte(struct spi_nor *nor, bool enable)
+ {
+ if (nor->spimem) {
+@@ -1259,6 +1275,10 @@ static int spi_nor_erase(struct mtd_info
+ if (ret)
+ return ret;
+
++ ret = spi_nor_check_set_addr_width(nor, instr->addr + instr->len);
++ if (ret < 0)
++ return ret;
++
+ /* whole-chip erase? */
+ if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
+ unsigned long timeout;
+@@ -1315,6 +1335,7 @@ static int spi_nor_erase(struct mtd_info
+ write_disable(nor);
+
+ erase_err:
++ spi_nor_check_set_addr_width(nor, 0);
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_ERASE);
+
+ return ret;
+@@ -1621,7 +1642,9 @@ static int spi_nor_lock(struct mtd_info
+ if (ret)
+ return ret;
+
++ spi_nor_check_set_addr_width(nor, ofs + len);
+ ret = nor->params.locking_ops->lock(nor, ofs, len);
++ spi_nor_check_set_addr_width(nor, 0);
+
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_UNLOCK);
+ return ret;
+@@ -1636,7 +1659,9 @@ static int spi_nor_unlock(struct mtd_inf
+ if (ret)
+ return ret;
+
++ spi_nor_check_set_addr_width(nor, ofs + len);
+ ret = nor->params.locking_ops->unlock(nor, ofs, len);
++ spi_nor_check_set_addr_width(nor, 0);
+
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
+ return ret;
+@@ -1651,7 +1676,9 @@ static int spi_nor_is_locked(struct mtd_
+ if (ret)
+ return ret;
+
++ spi_nor_check_set_addr_width(nor, ofs + len);
+ ret = nor->params.locking_ops->is_locked(nor, ofs, len);
++ spi_nor_check_set_addr_width(nor, 0);
+
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
+ return ret;
+@@ -2557,6 +2584,10 @@ static int spi_nor_read(struct mtd_info
+ if (ret)
+ return ret;
+
++ ret = spi_nor_check_set_addr_width(nor, from + len);
++ if (ret < 0)
++ return ret;
++
+ while (len) {
+ loff_t addr = from;
+
+@@ -2580,6 +2611,7 @@ static int spi_nor_read(struct mtd_info
+ ret = 0;
+
+ read_err:
++ spi_nor_check_set_addr_width(nor, 0);
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
+ return ret;
+ }
+@@ -2597,6 +2629,10 @@ static int sst_write(struct mtd_info *mt
+ if (ret)
+ return ret;
+
++ ret = spi_nor_check_set_addr_width(nor, to + len);
++ if (ret < 0)
++ return ret;
++
+ write_enable(nor);
+
+ nor->sst_write_second = false;
+@@ -2659,6 +2695,7 @@ static int sst_write(struct mtd_info *mt
+ }
+ sst_write_err:
+ *retlen += actual;
++ spi_nor_check_set_addr_width(nor, 0);
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
+ return ret;
+ }
+@@ -2681,6 +2718,10 @@ static int spi_nor_write(struct mtd_info
+ if (ret)
+ return ret;
+
++ ret = spi_nor_check_set_addr_width(nor, to + len);
++ if (ret < 0)
++ return ret;
++
+ for (i = 0; i < len; ) {
+ ssize_t written;
+ loff_t addr = to + i;
+@@ -2720,6 +2761,7 @@ static int spi_nor_write(struct mtd_info
+ }
+
+ write_err:
++ spi_nor_check_set_addr_width(nor, 0);
+ spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
+ return ret;
+ }
+@@ -4726,9 +4768,13 @@ static int spi_nor_init(struct spi_nor *
+ * reboots (e.g., crashes). Warn the user (or hopefully, system
+ * designer) that this is bad.
+ */
+- WARN_ONCE(nor->flags & SNOR_F_BROKEN_RESET,
+- "enabling reset hack; may not recover from unexpected reboots\n");
+- nor->params.set_4byte(nor, true);
++ if (nor->flags & SNOR_F_BROKEN_RESET) {
++ dev_warn(nor->dev,
++ "enabling reset hack; may not recover from unexpected reboots\n");
++ nor->addr_width = 3;
++ } else {
++ nor->params.set_4byte(nor, true);
++ }
+ }
+
+ return 0;