[PATCH v4 4/8] bus: mhi: core: Clear configuration from channel context during reset

From: Bhaumik Bhatt
Date: Thu Dec 03 2020 - 20:24:36 EST


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@xxxxxxxxxxxxxx>
---
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 5cdddb2..1b6962d 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -553,6 +553,7 @@ 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;
@@ -563,7 +564,19 @@ 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,
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project