On Thu, Jul 13, 2023 at 12:40:18PM +0530, Krishna chaitanya chundru wrote:
> If the MHI state is in M3 then the most probably the host kept the
s/then the/then
> device in D3 hot or D3 cold, due to that endpoint transctions will not
s/transctions/transactions
> be read by the host, so endpoint wakes up host to bring the host to D0
endpoint needs to wake up the host to bring the device to D0 state...
> which eventually bring back the MHI state to M0.
>
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> ---
> drivers/bus/mhi/ep/main.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
> index 6008818..46a888e 100644
> --- a/drivers/bus/mhi/ep/main.c
> +++ b/drivers/bus/mhi/ep/main.c
> @@ -25,6 +25,26 @@ static DEFINE_IDA(mhi_ep_cntrl_ida);
> static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id);
> static int mhi_ep_destroy_device(struct device *dev, void *data);
>
> +static int mhi_ep_wake_host(struct mhi_ep_cntrl *mhi_cntrl)
> +{
> + enum mhi_state state;
> + bool mhi_reset;
> + u32 count = 0;
> +
> + mhi_cntrl->wakeup_host(mhi_cntrl);
> +
> + /* Wait for Host to set the M0 state */
> + while (count++ < M0_WAIT_COUNT) {
> + msleep(M0_WAIT_DELAY_MS);
> +
> + mhi_ep_mmio_get_mhi_state(mhi_cntrl, &state, &mhi_reset);
> + if (state == MHI_STATE_M0)
> + return 0;
> + }
> +
> + return -ENODEV;
ENODEV or ETIMEDOUT?
> +}
> +
> static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx,
> struct mhi_ring_element *el, bool bei)
> {
> @@ -464,6 +484,13 @@ int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb)
> buf_left = skb->len;
> ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring;
>
> + if (mhi_cntrl->mhi_state == MHI_STATE_M3) {
> + if (mhi_ep_wake_host(mhi_cntrl)) {
Don't you need lock here in the case of multiple queue requests?
- Mani
> + dev_err(dev, "Failed to wakeup host\n");
> + return -ENODEV;
> + }
> + }
> +
> mutex_lock(&mhi_chan->lock);
>
> do {
> --
> 2.7.4
>
--
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