[PATCH] fs: jffs2: Add setup code for spi nor flash.

[Sourav Poddar]

Flash need to be setup, while using it for Jffs2 filesystem.
The setup code checks was not present for serial flash like
m25p80. As a result of which, internal pointers/buffers are in unknown
state. This leads to
a. dumps like below[1] while mounting a jffs2 filesystem.
b. Hang while doing a mount second time.

[1]:
root at am437x-evm:~# sync
[   84.112640] INFO: trying to register non-static key.
[   84.117553] the code is fine but needs lockdep annotation.
[   84.122985] turning off the locking correctness validator.
[   84.128417] CPU: 0 PID: 1289 Comm: sync Not tainted 3.12.0-67367-g2d1978c-dirty #18
[   84.136016] [<c001bcb8>] (unwind_backtrace+0x0/0xf0) from [<c0017dd0>] (show_stack+0x10/0x14)
[   84.144439] [<c0017dd0>] (show_stack+0x10/0x14) from [<c05a69c8>] (dump_stack+0x78/0x94)
[   84.152465] [<c05a69c8>] (dump_stack+0x78/0x94) from [<c009e2e0>] (__lock_acquire+0x1788/0x1b8c)
[   84.161132] [<c009e2e0>] (__lock_acquire+0x1788/0x1b8c) from [<c009ec30>] (lock_acquire+0x9c/0x104)
[   84.170104] [<c009ec30>] (lock_acquire+0x9c/0x104) from [<c005ede8>] (flush_work+0x38/0x78)
[   84.178375] [<c005ede8>] (flush_work+0x38/0x78) from [<c005eef0>] (__cancel_work_timer+0x84/0x124)
[   84.187225] [<c005eef0>] (__cancel_work_timer+0x84/0x124) from [<c024c1d4>] (jffs2_sync_fs+0x14/0x38)
[   84.196380] [<c024c1d4>] (jffs2_sync_fs+0x14/0x38) from [<c013c138>] (sync_fs_one_sb+0x28/0x2c)
[   84.204986] [<c013c138>] (sync_fs_one_sb+0x28/0x2c) from [<c0115360>] (iterate_supers+0xb0/0xd8)
[   84.213684] [<c0115360>] (iterate_supers+0xb0/0xd8) from [<c013c228>] (sys_sync+0x3c/0x98)
[   84.221862] [<c013c228>] (sys_sync+0x3c/0x98) from [<c0013dc0>] (ret_fast_syscall+0x0/0x48)

The patch fixes the above two issue.

Signed-off-by: Sourav Poddar <sourav.poddar at ti.com>
Signed-off-by: George Cherian <george.cherian at ti.com>
---
 fs/jffs2/fs.c       |    7 +++++++
 fs/jffs2/os-linux.h |    2 ++
 2 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index fe3c052..02003f0 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -725,6 +725,13 @@ static int jffs2_flash_setup(struct jffs2_sb_info *c) {
 			return ret;
 	}
 
+	/* m25p80 spi flash */
+	if (jffs2_nor_spi_wbuf_flash(c)) {
+		ret = jffs2_nor_wbuf_flash_setup(c);
+		if (ret)
+			return ret;
+	}
+
 	/* and an UBI volume */
 	if (jffs2_ubivol(c)) {
 		ret = jffs2_ubivol_setup(c);
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index d200a9b..09ba999 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -134,6 +134,8 @@ int jffs2_ubivol_setup(struct jffs2_sb_info *c);
 void jffs2_ubivol_cleanup(struct jffs2_sb_info *c);
 
 #define jffs2_nor_wbuf_flash(c) (c->mtd->type == MTD_NORFLASH && ! (c->mtd->flags & MTD_BIT_WRITEABLE))
+#define jffs2_nor_spi_wbuf_flash(c) \
+	(c->mtd->type == MTD_NORFLASH && (c->mtd->flags & MTD_CAP_NORFLASH))
 int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c);
 void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c);
 void jffs2_dirty_trigger(struct jffs2_sb_info *c);
-- 
1.7.1