Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Slark Xiao <slark_xiao@163.com>
To:     loic.poulain@linaro.org, ryazanov.s.a@gmail.com,
        johannes@sipsolutions.net, davem@davemloft.net, kuba@kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Slark Xiao <slark_xiao@163.com>, Shujun Wang <wsj20369@163.com>
Subject: [PATCH net] net: wwan: Fix MRU mismatch issue which may lead to data connection lost
Date:   Sat, 15 Jan 2022 10:34:30 +0800
Message-Id: <20220115023430.4659-1-slark_xiao@163.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

In pci_generic.c there is a 'mru_default' in struct mhi_pci_dev_info.
This value shall be used for whole mhi if it's given a value for a specific product.
But in function mhi_net_rx_refill_work(), it's still using hard code value MHI_DEFAULT_MRU.
'mru_default' shall have higher priority than MHI_DEFAULT_MRU.
And after checking, this change could help fix a data connection lost issue.

Fixes: 5c2c85315948 ("bus: mhi: pci-generic: configurable network interface MRU")
Signed-off-by: Shujun Wang <wsj20369@163.com>
Signed-off-by: Slark Xiao <slark_xiao@163.com>
---
 drivers/net/wwan/mhi_wwan_mbim.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wwan/mhi_wwan_mbim.c b/drivers/net/wwan/mhi_wwan_mbim.c
index 71bf9b4f769f..6872782e8dd8 100644
--- a/drivers/net/wwan/mhi_wwan_mbim.c
+++ b/drivers/net/wwan/mhi_wwan_mbim.c
@@ -385,13 +385,13 @@ static void mhi_net_rx_refill_work(struct work_struct *work)
 	int err;
 
 	while (!mhi_queue_is_full(mdev, DMA_FROM_DEVICE)) {
-		struct sk_buff *skb = alloc_skb(MHI_DEFAULT_MRU, GFP_KERNEL);
+		struct sk_buff *skb = alloc_skb(mbim->mru, GFP_KERNEL);
 
 		if (unlikely(!skb))
 			break;
 
 		err = mhi_queue_skb(mdev, DMA_FROM_DEVICE, skb,
-				    MHI_DEFAULT_MRU, MHI_EOT);
+				    mbim->mru, MHI_EOT);
 		if (unlikely(err)) {
 			kfree_skb(skb);
 			break;
-- 
2.25.1