aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.1/0110-mailbox-bcm2835-Fix-mailbox-full-detection.patch
blob: 43c2560911d304f50532728b50a81f1f0d0dfd56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
From dbacf38b4227ffcd9a7eafdb49d395208229286c Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 13 May 2015 13:10:32 -0700
Subject: [PATCH 110/203] mailbox/bcm2835: Fix mailbox full detection.

With the VC reader blocked and the ARM writing, MAIL0_STA reads empty
permanently while MAIL1_STA goes from empty (0x40000000) to non-empty
(0x00000001-0x00000007) to full (0x80000008).

This bug ended up having no effect on us, because all of our
transactions in the client driver were synchronous and under a mutex.

Suggested-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
---
 drivers/mailbox/bcm2835-mailbox.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/mailbox/bcm2835-mailbox.c
+++ b/drivers/mailbox/bcm2835-mailbox.c
@@ -49,6 +49,7 @@
 #define MAIL0_STA	(ARM_0_MAIL0 + 0x18)
 #define MAIL0_CNF	(ARM_0_MAIL0 + 0x1C)
 #define MAIL1_WRT	(ARM_0_MAIL1 + 0x00)
+#define MAIL1_STA	(ARM_0_MAIL1 + 0x18)
 
 /* Status register: FIFO state. */
 #define ARM_MS_FULL		BIT(31)
@@ -117,7 +118,7 @@ static bool bcm2835_last_tx_done(struct
 	bool ret;
 
 	spin_lock(&mbox->lock);
-	ret = !(readl(mbox->regs + MAIL0_STA) & ARM_MS_FULL);
+	ret = !(readl(mbox->regs + MAIL1_STA) & ARM_MS_FULL);
 	spin_unlock(&mbox->lock);
 	return ret;
 }