On Tue, Nov 07, 2023 at 03:16:02PM +0800, Qiang Yu wrote:
> From: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
>
> Protect WP accesses such that multiple threads queueing buffers for
> incoming data do not race.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Fixes: 189ff97cca53 ("bus: mhi: core: Add support for data transfer")
> Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
> Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
- Mani
> ---
> drivers/bus/mhi/host/main.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> index 6cf1145..c9415b0 100644
> --- a/drivers/bus/mhi/host/main.c
> +++ b/drivers/bus/mhi/host/main.c
> @@ -1205,6 +1205,9 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
> int eot, eob, chain, bei;
> int ret;
>
> + /* Protect accesses for reading and incrementing WP */
> + write_lock_bh(&mhi_chan->lock);
> +
> buf_ring = &mhi_chan->buf_ring;
> tre_ring = &mhi_chan->tre_ring;
>
> @@ -1222,8 +1225,10 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
>
> if (!info->pre_mapped) {
> ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
> - if (ret)
> + if (ret) {
> + write_unlock_bh(&mhi_chan->lock);
> return ret;
> + }
> }
>
> eob = !!(flags & MHI_EOB);
> @@ -1240,6 +1245,8 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
> mhi_add_ring_element(mhi_cntrl, tre_ring);
> mhi_add_ring_element(mhi_cntrl, buf_ring);
>
> + write_unlock_bh(&mhi_chan->lock);
> +
> return 0;
> }
>
> --
> 2.7.4
>
>
--
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