On 2021-02-10 12:25 AM, Manivannan Sadhasivam wrote:
From: Loic Poulain <loic.poul...@linaro.org>

mhi_deinit_chan_ctxt functionthat takes care of unitializing channel
s/functionthat/function that, uninitializing
resources, including unmapping coherent MHI areas, can be called
from different path in case of controller unregistering/removal:
 - From a client driver remove callback, via mhi_unprepare_channel
 - From mhi_driver_remove that unitialize all channels
uninitialize

mhi_driver_remove()
|-> driver->remove()
|    |-> mhi_unprepare_channel()
|        |-> mhi_deinit_chan_ctxt()
|...
|-> mhi_deinit_chan_ctxt()

This leads to double dma freeing...

Fix that by preventing deinit for already uninitialized channel.

Fixes: a7f422f2f89e ("bus: mhi: Fix channel close issue on driver remove")
Signed-off-by: Loic Poulain <loic.poul...@linaro.org>
Reported-by: Kalle Valo <kv...@codeaurora.org>
Tested-by: Kalle Valo <kv...@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>
Link:
https://lore.kernel.org/r/1612894264-15956-1-git-send-email-loic.poul...@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>
---
 drivers/bus/mhi/core/init.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index aa575d3fb3ae..be4eebb0971b 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -557,6 +557,9 @@ void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
        tre_ring = &mhi_chan->tre_ring;
        chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];

+       if (!chan_ctxt->rbase) /* Already uninitialized */
+               return;
+
        mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
                          tre_ring->pre_aligned, tre_ring->dma_handle);
        vfree(buf_ring->base);

As mentioned in my previous email, I see some improvements can be made to the commit
message and title of this patch. Highlighted those above.

Please update title to "bus: mhi: core: Fix double DMA free from mhi_deinit_chan_ctxt()".

Thanks,
Bhaumik
---
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