Re: [PATCH] PM / MTD: Fix regressions related to mtd_suspend()

[Artem Bityutskiy]

Thanks Rafael!

I've pushed this patch to l2-mtd-2.6.git (David, would you please merge
it upstream?).

Rafael, should I add some tags with your name like Tested-by or
Acked-by?


From d0eb0d769923d562781fcf43fdc6fa28e3823756 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
Date: Mon, 16 Jan 2012 11:07:16 +0200
Subject: [PATCH] mtd: fix MTD suspend

Commits 3fe4bae88460869a8e553397cd9057a4ee7ca341 and
079c985e7a6f4ce60f931cebfdd5ee3c3 broke MTD suspend in 2 ways:

1. When the '->suspend' method is not present, we return -EOPNOTSUPP, but
   the callers of 'mtd_suspend()' expects 0 instead.
2. Checking of the 'mtd' parameter against NULL has been incorrectly removed
   in 'mtd_cls_suspend()'.

This patch fixes the breakages. This has been found, analyzed, reported
and tested by Rafael J. Wysocki <rjw@xxxxxxx>.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
---
 drivers/mtd/mtdcore.c   |    2 +-
 include/linux/mtd/mtd.h |    4 +---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index b265188..de96865 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -119,7 +119,7 @@ static int mtd_cls_suspend(struct device *dev, pm_message_t state)
 {
        struct mtd_info *mtd = dev_get_drvdata(dev);
 
-       return mtd_suspend(mtd);
+       return mtd ? mtd_suspend(mtd) : 0;
 }
 
 static int mtd_cls_resume(struct device *dev)
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 1a81fde..d8c7aad 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -427,9 +427,7 @@ static inline int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 
 static inline int mtd_suspend(struct mtd_info *mtd)
 {
-       if (!mtd->suspend)
-               return -EOPNOTSUPP;
-       return mtd->suspend(mtd);
+       return mtd->suspend ? mtd->suspend(mtd) : 0;
 }
 
 static inline void mtd_resume(struct mtd_info *mtd)
-- 
1.7.8.3


-- 
Best Regards,
Artem Bityutskiy

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