Messages in this thread | | | Date | Fri, 28 Jul 2023 10:04:52 +0530 | From | Manivannan Sadhasivam <> | Subject | Re: [PATCH v4 9/9] bus: mhi: ep: wake up host if the MHI state is in M3 |
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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@quicinc.com> > --- > 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 >
-- மணிவண்ணன் சதாசிவம்
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