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:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Shujun Wang <wsj20369@163.com>,
        Slark Xiao <slark_xiao@163.com>,
        Loic Poulain <loic.poulain@linaro.org>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 5.16 1015/1039] net: wwan: Fix MRU mismatch issue which may lead to data connection lost
Date:   Mon, 24 Jan 2022 19:46:44 +0100
Message-Id: <20220124184159.412744533@linuxfoundation.org>
In-Reply-To: <20220124184125.121143506@linuxfoundation.org>
References: <20220124184125.121143506@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Slark Xiao <slark_xiao@163.com>

commit f542cdfa3083a309e3caafbbdf41490c4935492a upstream.

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>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/wwan/mhi_wwan_mbim.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- 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(struc
 	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;