openwrt/target/linux/brcm2708/patches-4.1/0110-mailbox-bcm2835-Fix-mailbox-full-detection.patch

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From ca4917d04782e7f51ceb818658896a3c44bcb1c6 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 13 May 2015 13:10:32 -0700
Subject: [PATCH 110/222] 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;
}