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From:   Bhaumik Bhatt <bbhatt@codeaurora.org>
To:     manivannan.sadhasivam@linaro.org
Cc:     linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
        jhugo@codeaurora.org, linux-kernel@vger.kernel.org,
        carl.yin@quectel.com, naveen.kumar@quectel.com,
        loic.poulain@linaro.org, Bhaumik Bhatt <bbhatt@codeaurora.org>
Subject: [PATCH v7 4/7] bus: mhi: core: Clear configuration from channel context during reset
Date:   Mon, 29 Mar 2021 19:11:44 -0700
Message-Id: <1617070307-5775-5-git-send-email-bbhatt@codeaurora.org>
In-Reply-To: <1617070307-5775-1-git-send-email-bbhatt@codeaurora.org>
References: <1617070307-5775-1-git-send-email-bbhatt@codeaurora.org>
Precedence: bulk

When clearing up the channel context after client drivers are
done using channels, the configuration is currently not being
reset entirely. Ensure this is done to appropriately handle
issues where clients unaware of the context state end up calling
functions which expect a context.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 64846c4..8b840da 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -556,6 +556,7 @@ void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
 	struct mhi_ring *buf_ring;
 	struct mhi_ring *tre_ring;
 	struct mhi_chan_ctxt *chan_ctxt;
+	u32 tmp;
 
 	buf_ring = &mhi_chan->buf_ring;
 	tre_ring = &mhi_chan->tre_ring;
@@ -569,7 +570,19 @@ void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
 	vfree(buf_ring->base);
 
 	buf_ring->base = tre_ring->base = NULL;
+	tre_ring->ctxt_wp = NULL;
 	chan_ctxt->rbase = 0;
+	chan_ctxt->rlen = 0;
+	chan_ctxt->rp = 0;
+	chan_ctxt->wp = 0;
+
+	tmp = chan_ctxt->chcfg;
+	tmp &= ~CHAN_CTX_CHSTATE_MASK;
+	tmp |= (MHI_CH_STATE_DISABLED << CHAN_CTX_CHSTATE_SHIFT);
+	chan_ctxt->chcfg = tmp;
+
+	/* Update to all cores */
+	smp_wmb();
 }
 
 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
-- 
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