[OpenWrt-Devel] [PATCH] ipq40xx: essedma: Fix dead lock

[Masafumi UTSUGI]

edma_read_append_stats() is called from kernel timer
(Bottom half context) but it used spin_lock() to take a lock.
Using ethtool command rarely causes deadlock because of this.
Change lock function to spin_lock_bh() to avoid this.

Signed-off-by: Masafumi UTSUGI <mutsugi at allied-telesis.co.jp>
---
 .../patches-4.14/715-essedma-fix-dead-lock.patch     | 20 ++++++++++++++++++++
 .../patches-4.19/715-essedma-fix-dead-lock.patch     | 20 ++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 target/linux/ipq40xx/patches-4.14/715-essedma-fix-dead-lock.patch
 create mode 100644 target/linux/ipq40xx/patches-4.19/715-essedma-fix-dead-lock.patch

diff --git a/target/linux/ipq40xx/patches-4.14/715-essedma-fix-dead-lock.patch b/target/linux/ipq40xx/patches-4.14/715-essedma-fix-dead-lock.patch
new file mode 100644
index 0000000..1c44924
--- /dev/null
+++ b/target/linux/ipq40xx/patches-4.14/715-essedma-fix-dead-lock.patch
@@ -0,0 +1,20 @@
+--- a/drivers/net/ethernet/qualcomm/essedma/edma_axi.c
++++ b/drivers/net/ethernet/qualcomm/essedma/edma_axi.c
+@@ -230,7 +230,7 @@
+ 	int i;
+ 	u32 stat;
+ 
+-	spin_lock(&edma_cinfo->stats_lock);
++	spin_lock_bh(&edma_cinfo->stats_lock);
+ 	p = (uint32_t *)&(edma_cinfo->edma_ethstats);
+ 
+ 	for (i = 0; i < EDMA_MAX_TRANSMIT_QUEUE; i++) {
+@@ -257,7 +257,7 @@
+ 		p++;
+ 	}
+ 
+-	spin_unlock(&edma_cinfo->stats_lock);
++	spin_unlock_bh(&edma_cinfo->stats_lock);
+ }
+ 
+ static void edma_statistics_timer(unsigned long data)
diff --git a/target/linux/ipq40xx/patches-4.19/715-essedma-fix-dead-lock.patch b/target/linux/ipq40xx/patches-4.19/715-essedma-fix-dead-lock.patch
new file mode 100644
index 0000000..1c44924
--- /dev/null
+++ b/target/linux/ipq40xx/patches-4.19/715-essedma-fix-dead-lock.patch
@@ -0,0 +1,20 @@
+--- a/drivers/net/ethernet/qualcomm/essedma/edma_axi.c
++++ b/drivers/net/ethernet/qualcomm/essedma/edma_axi.c
+@@ -230,7 +230,7 @@
+ 	int i;
+ 	u32 stat;
+ 
+-	spin_lock(&edma_cinfo->stats_lock);
++	spin_lock_bh(&edma_cinfo->stats_lock);
+ 	p = (uint32_t *)&(edma_cinfo->edma_ethstats);
+ 
+ 	for (i = 0; i < EDMA_MAX_TRANSMIT_QUEUE; i++) {
+@@ -257,7 +257,7 @@
+ 		p++;
+ 	}
+ 
+-	spin_unlock(&edma_cinfo->stats_lock);
++	spin_unlock_bh(&edma_cinfo->stats_lock);
+ }
+ 
+ static void edma_statistics_timer(unsigned long data)
-- 
2.7.4


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