CHIPS: Fix potential starvation in cfi_cmdset_0001

The patch below fixes a potential starvation issue that can arise when
there is contention on a chip during a period when a process is
currently writing to it.  The starvation is avoided by conditionally
rescheduling when the chip is left in a state usable by other processes.

Signed-off-by: Josh Boyer <jdub@us.ibm.com>
Signed-off-by: Tom Gall <tom_gall@vnet.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 898c321ab86d..e797752f7c0b 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -1691,6 +1691,11 @@ static int cfi_intelext_writev (struct mtd_info *mtd, const struct kvec *vecs,
                         if (chipnum == cfi->numchips)
                                 return 0;
                 }
+
+                /* Be nice and reschedule with the chip in a usable state for other
+                   processes. */
+                cond_resched();
+
         } while (len);
 
         return 0;