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 <p...@raspberrypi.org>
Signed-off-by: Eric Anholt <e...@anholt.net>
---
This is a port of a patch by Noralf from the downstream Raspberry Pi
tree. Noralf said he didn't want attribution on this patch, even if
it looks a lot like his.
drivers/mailbox/bcm2835-mailbox.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/mailbox/bcm2835-mailbox.c
b/drivers/mailbox/bcm2835-mailbox.c
index 4b13268..0b47dd4 100644
--- 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 mbox_chan *link)
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;
}
--
2.1.4
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