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From:   Qiang Yu <quic_qianyu@quicinc.com>
To:     mani@kernel.org, quic_jhugo@quicinc.com
Cc:     mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, quic_cang@quicinc.com,
        quic_mrana@quicinc.com, Qiang Yu <quic_qianyu@quicinc.com>
Subject: [PATCH v3 3/4] bus: mhi: host: Avoid processing buffer and event of a disable channel
Date:   Tue,  7 Nov 2023 15:16:04 +0800
Message-Id: <1699341365-47737-4-git-send-email-quic_qianyu@quicinc.com>
In-Reply-To: <1699341365-47737-1-git-send-email-quic_qianyu@quicinc.com>
References: <1699341365-47737-1-git-send-email-quic_qianyu@quicinc.com>
Precedence: bulk

Ckeck mhi channel state after getting chan->lock to ensure that we only
queue buffer to an enabled channel and process event of an enabled channel.

Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com>
---
 drivers/bus/mhi/host/main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index a236dc2..b137d54 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -672,6 +672,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl,
 			}
 
 			read_lock_bh(&mhi_chan->lock);
+			if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
+				goto end_process_tx_event;
 		}
 		break;
 	} /* CC_EOT */
@@ -1211,6 +1213,8 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
 
 	/* Protect accesses for reading and incrementing WP */
 	write_lock_bh(&mhi_chan->lock);
+	if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
+		return -EINVAL;
 
 	buf_ring = &mhi_chan->buf_ring;
 	tre_ring = &mhi_chan->tre_ring;
-- 
2.7.4