On Tue, Feb 09, 2021 at 07:11:04PM +0100, Loic Poulain wrote:
> mhi_deinit_chan_ctxt functionthat takes care of unitializing channel
> 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
>
> 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.poulain@xxxxxxxxxx>
> Reported-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
> Tested-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Thanks,
Mani
> ---
> v2: add Fixes tag
>
> 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 aa575d3..be4eebb 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);
> --
> 2.7.4
>
