From 5ffc6b5a98404db51529c427ccbccd4878593cea Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Mon, 20 Jan 2020 12:07:09 +0100
Subject: [PATCH] mt76: set dma-done flag for flushed descriptors
Git-commit: 5ffc6b5a98404db51529c427ccbccd4878593cea
References: git-fixes
Patch-mainline: v5.7-rc1
Avoids a theoretical corner case where the hardware could try to process
a stale descriptor after a watchdog reset
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/net/wireless/mediatek/mt76/dma.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 9e03a7871ff4..e69329feed78 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -246,7 +246,9 @@ mt76_dma_dequeue(struct mt76_dev *dev, struct mt76_queue *q, bool flush,
if (!q->queued)
return NULL;
- if (!flush && !(q->desc[idx].ctrl & cpu_to_le32(MT_DMA_CTL_DMA_DONE)))
+ if (flush)
+ q->desc[idx].ctrl |= cpu_to_le32(MT_DMA_CTL_DMA_DONE);
+ else if (!(q->desc[idx].ctrl & cpu_to_le32(MT_DMA_CTL_DMA_DONE)))
return NULL;
q->tail = (q->tail + 1) % q->ndesc;
--
2.26.2