[tip:irq/core] genirq/proc: Return proper error code when irq_set_affinity() fails

[tip-bot for Wen Yaxng]

Commit-ID:  6714796edcce27f7a1845e2f79783cd51bb4799b
Gitweb:     https://git.kernel.org/tip/6714796edcce27f7a1845e2f79783cd51bb4799b
Author:     Wen Yaxng <wen.yang99@xxxxxxxxxx>
AuthorDate: Wed, 8 Nov 2017 09:55:03 +0800
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sun, 12 Nov 2017 23:25:39 +0100

genirq/proc: Return proper error code when irq_set_affinity() fails

write_irq_affinity() returns the number of written bytes, which means
success, unconditionally whether the actual irq_set_affinity() call
succeeded or not.

Add proper error handling and pass the error code returned from
irq_set_affinity() back to user space in case of failure.

[ tglx: Fixed coding style and massaged changelog ]

Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Jiang Biao <jiang.biao2@xxxxxxxxxx>
Cc: zhong.weidong@xxxxxxxxxx
Link: https://lkml.kernel.org/r/1510106103-184761-1-git-send-email-wen.yang99@xxxxxxxxxx

---
 kernel/irq/proc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 6376b4a..29d6f52 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -154,8 +154,9 @@ static ssize_t write_irq_affinity(int type, struct file *file,
 		 */
 		err = irq_select_affinity_usr(irq) ? -EINVAL : count;
 	} else {
-		irq_set_affinity(irq, new_value);
-		err = count;
+		err = irq_set_affinity(irq, new_value);
+		if (!err)
+			err = count;
 	}
 
 free_cpumask: