openwrt/target/linux/mvebu/patches-4.4/038-net-mvneta-Fix-the-CPU-choice-in-mvneta_percpu_elect.patch
Koen Vandeputte 65044a50ab kernel: bump 4.4 to 4.4.167
Refreshed all patches.

Removed upstreamed:
- 203-MIPS-ath79-fix-restart.patch
- 330-Revert-MIPS-BCM47XX-Enable-74K-Core-ExternalSync-for.patch
- 051-0001-ovl-rename-is_merge-to-is_lowest.patch
- 051-0002-ovl-override-creds-with-the-ones-from-the-superblock.patch
- 051-0005-ovl-proper-cleanup-of-workdir.patch

Altered patches:
- 201-extra_optimization.patch
- 304-mips_disable_fpu.patch

Compile-tested on: ar71xx, cns3xxx, imx6, mpc85xx
Runtime-tested on: ar71xx, cns3xxx, imx6, mpc85xx

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
2018-12-18 15:14:39 +01:00

58 lines
2.1 KiB
Diff

From: Gregory CLEMENT <gregory.clement@free-electrons.com>
Date: Thu, 4 Feb 2016 22:09:24 +0100
Subject: [PATCH] net: mvneta: Fix the CPU choice in mvneta_percpu_elect
When passing to the management of multiple RX queue, the
mvneta_percpu_elect function was broken. The use of the modulo can lead
to elect the wrong cpu. For example with rxq_def=2, if the CPU 2 goes
offline and then online, we ended with the third RX queue activated in
the same time on CPU 0 and CPU2, which lead to a kernel crash.
With this fix, we don't try to get "the closer" CPU if the default CPU is
gone, now we just use CPU 0 which always be there. Thanks to this, the
code becomes more readable, easier to maintain and more predicable.
Cc: stable@vger.kernel.org
Fixes: 2dcf75e2793c ("net: mvneta: Associate RX queues with each CPU")
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2851,9 +2851,14 @@ static void mvneta_percpu_disable(void *
static void mvneta_percpu_elect(struct mvneta_port *pp)
{
- int online_cpu_idx, max_cpu, cpu, i = 0;
+ int elected_cpu = 0, max_cpu, cpu, i = 0;
+
+ /* Use the cpu associated to the rxq when it is online, in all
+ * the other cases, use the cpu 0 which can't be offline.
+ */
+ if (cpu_online(pp->rxq_def))
+ elected_cpu = pp->rxq_def;
- online_cpu_idx = pp->rxq_def % num_online_cpus();
max_cpu = num_present_cpus();
for_each_online_cpu(cpu) {
@@ -2864,7 +2869,7 @@ static void mvneta_percpu_elect(struct m
if ((rxq % max_cpu) == cpu)
rxq_map |= MVNETA_CPU_RXQ_ACCESS(rxq);
- if (i == online_cpu_idx)
+ if (cpu == elected_cpu)
/* Map the default receive queue queue to the
* elected CPU
*/
@@ -2875,7 +2880,7 @@ static void mvneta_percpu_elect(struct m
* the CPU bound to the default RX queue
*/
if (txq_number == 1)
- txq_map = (i == online_cpu_idx) ?
+ txq_map = (cpu == elected_cpu) ?
MVNETA_CPU_TXQ_ACCESS(1) : 0;
else
txq_map = mvreg_read(pp, MVNETA_CPU_MAP(cpu)) &