mtd: CFI cmdset_0002: enable erase-suspend-program
Erase-suspend for writing is required to avoid blocking applications
that wish to write some data (to a NOR block other than the one being
erased). Particularly, it solves some huge delays that an application
(which writes to a UBIFS) will experience if UBI attaches to empty NOR
flash. In this case the UBI background thread will erase a lot of blocks
and the application can be blocked for minutes because of the "MTD/CFI
chip lock".
This feature has been disabled for years. Maybe this was because the old
code turned it on for erase-suspend read-only chips also
(cfip->EraseSuspend & 0x1). This is wrong and corrected now.
This patch was tweaked by Norbert van Bolhuis.
Signed-off-by: Norbert van Bolhuis <nvbolhuis@aimvalley.nl>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 94bb61e..1d49e18 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -490,10 +490,6 @@
}
#endif
- /* FIXME: erase-suspend-program is broken. See
- http://lists.infradead.org/pipermail/linux-mtd/2003-December/009001.html */
- printk(KERN_NOTICE "cfi_cmdset_0002: Disabling erase-suspend-program due to code brokenness.\n");
-
__module_get(THIS_MODULE);
return mtd;
@@ -589,15 +585,9 @@
return 0;
case FL_ERASING:
- if (mode == FL_WRITING) /* FIXME: Erase-suspend-program appears broken. */
- goto sleep;
-
- if (!( mode == FL_READY
- || mode == FL_POINT
- || !cfip
- || (mode == FL_WRITING && (cfip->EraseSuspend & 0x2))
- || (mode == FL_WRITING && (cfip->EraseSuspend & 0x1)
- )))
+ if (!cfip || !(cfip->EraseSuspend & (0x1|0x2)) ||
+ !(mode == FL_READY || mode == FL_POINT ||
+ (mode == FL_WRITING && (cfip->EraseSuspend & 0x2))))
goto sleep;
/* We could check to see if we're trying to access the sector
