From 8e06e9fb990975a55b64c6e4c5b6b183962f849a Mon Sep 17 00:00:00 2001 From: Bhaumik Bhatt Date: Thu, 1 Apr 2021 14:16:16 -0700 Subject: [PATCH] bus: mhi: core: Check channel execution environment before issuing reset A client can attempt to unprepare certain channels for transfer even after the execution environment they are supposed to run in has changed. In the event that happens, the device need not be notified of the reset and the host can proceed with clean up for the channel context and memory allocated for it on the host as the device will no longer be able to respond to such a request. Signed-off-by: Bhaumik Bhatt Reviewed-by: Hemant Kumar Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/1617311778-1254-8-git-send-email-bbhatt@codeaurora.org Signed-off-by: Manivannan Sadhasivam --- drivers/bus/mhi/core/main.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index b4b87a9e17a4..0be1e7747cd7 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -1337,6 +1337,12 @@ static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl, mutex_lock(&mhi_chan->mutex); + if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) { + dev_dbg(dev, "Current EE: %s Required EE Mask: 0x%x\n", + TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask); + goto exit_unprepare_channel; + } + /* no more processing events for this channel */ ret = mhi_update_channel_state(mhi_cntrl, mhi_chan, MHI_CH_STATE_TYPE_RESET); @@ -1344,6 +1350,11 @@ static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl, dev_err(dev, "%d: Failed to reset channel, still resetting\n", mhi_chan->chan); +exit_unprepare_channel: + write_lock_irq(&mhi_chan->lock); + mhi_chan->ch_state = MHI_CH_STATE_DISABLED; + write_unlock_irq(&mhi_chan->lock); + if (!mhi_chan->offload_ch) { mhi_reset_chan(mhi_cntrl, mhi_chan); mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);