Messages in this thread | | | Date | Tue, 22 Feb 2022 13:48:59 +0530 | From | Manivannan Sadhasivam <> | Subject | Re: [PATCH v3 15/25] bus: mhi: ep: Add support for processing MHI endpoint interrupts |
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On Tue, Feb 15, 2022 at 04:39:30PM -0600, Alex Elder wrote: > On 2/12/22 12:21 PM, Manivannan Sadhasivam wrote: > > Add support for processing MHI endpoint interrupts such as control > > interrupt, command interrupt and channel interrupt from the host. > > > > The interrupts will be generated in the endpoint device whenever host > > writes to the corresponding doorbell registers. The doorbell logic > > is handled inside the hardware internally. > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > Unless I'm mistaken, you have some bugs here. > > Beyond that, I question whether you should be using workqueues > for handling all interrupts. For now, it's fine, but there > might be room for improvement after this is accepted upstream > (using threaded interrupt handlers, for example). >
Only reason I didn't use bottom halves is that the memory for TRE buffers need to be allocated each time, so essentially the caller should not sleep.
This is currently a limitation of iATU where there are only 8 windows for mapping the host memory and each memory region size is also limited.
> -Alex > > > --- > > drivers/bus/mhi/ep/main.c | 113 +++++++++++++++++++++++++++++++++++++- > > include/linux/mhi_ep.h | 2 + > > 2 files changed, 113 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c > > index ccb3c2795041..072b872e735b 100644 > > --- a/drivers/bus/mhi/ep/main.c > > +++ b/drivers/bus/mhi/ep/main.c > > @@ -185,6 +185,56 @@ static void mhi_ep_ring_worker(struct work_struct *work) > > } > > } > > +static void mhi_ep_queue_channel_db(struct mhi_ep_cntrl *mhi_cntrl, > > + unsigned long ch_int, u32 ch_idx) > > +{ > > + struct device *dev = &mhi_cntrl->mhi_dev->dev; > > + struct mhi_ep_ring_item *item; > > + struct mhi_ep_ring *ring; > > + unsigned int i; > > Why not u32 i? And why is the ch_int argument unsigned long? The value > passed in is a u32. >
for_each_set_bit() expects the 2nd argument to be of type "unsigned long".
Thanks, Mani
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