From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Alex Elder <elder@ieee.org>
Cc: mhi@lists.linux.dev, hemantk@codeaurora.org,
bbhatt@codeaurora.org, quic_jhugo@quicinc.com,
vinod.koul@linaro.org, bjorn.andersson@linaro.org,
dmitry.baryshkov@linaro.org, skananth@codeaurora.org,
vpernami@codeaurora.org, vbadigan@codeaurora.org,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 07/20] bus: mhi: ep: Add support for creating and destroying MHI EP devices
Date: Thu, 3 Feb 2022 20:43:31 +0530 [thread overview]
Message-ID: <20220203151331.GF6298@thinkpad> (raw)
In-Reply-To: <08a3b725-d211-b363-a3b4-2a325367b976@ieee.org>
On Wed, Jan 05, 2022 at 06:28:08PM -0600, Alex Elder wrote:
> On 12/2/21 5:35 AM, Manivannan Sadhasivam wrote:
> > This commit adds support for creating and destroying MHI endpoint devices.
> > The MHI endpoint devices binds to the MHI endpoint channels and are used
> > to transfer data between MHI host and endpoint device.
> >
> > There is a single MHI EP device for each channel pair. The devices will be
> > created when the corresponding channels has been started by the host and
> > will be destroyed during MHI EP power down and reset.
> >
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> > drivers/bus/mhi/ep/main.c | 85 +++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 85 insertions(+)
> >
> > diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
> > index ce0f99f22058..f0b5f49db95a 100644
> > --- a/drivers/bus/mhi/ep/main.c
> > +++ b/drivers/bus/mhi/ep/main.c
> > @@ -63,6 +63,91 @@ static struct mhi_ep_device *mhi_ep_alloc_device(struct mhi_ep_cntrl *mhi_cntrl)
> > return mhi_dev;
> > }
> > +static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id)
> > +{
> > + struct mhi_ep_device *mhi_dev;
> > + struct mhi_ep_chan *mhi_chan = &mhi_cntrl->mhi_chan[ch_id];
> > + int ret;
> > +
> > + mhi_dev = mhi_ep_alloc_device(mhi_cntrl);
> > + if (IS_ERR(mhi_dev))
> > + return PTR_ERR(mhi_dev);
> > +
> > + mhi_dev->dev_type = MHI_DEVICE_XFER;
>
> Elsewhere (at least in mhi_ep_process_tre_ring()) in your code
> you assume that the even-numbered channel is UL.
>
> I would say, either use that assumption throughout, or do
> not use that assumption at all. (I prefer the latter.)
>
> I don't really like how this assumes that the channels
> are defined in adjacent pairs. It assumes one is
> upload and the next one is download, but doesn't
> specify the order in which they're defined. If
> you're going to assume they are defined in pairs, you
> should be able to assume which one is defined first,
> and then simplify this code (and even verify that
> they are defined UL before DL, perhaps).
>
Yes, the UL channel is always even numbered and DL is odd.
I've removed the checks.
> > + /* Configure primary channel */
> > + if (mhi_chan->dir == DMA_TO_DEVICE) {
> > + mhi_dev->ul_chan = mhi_chan;
> > + mhi_dev->ul_chan_id = mhi_chan->chan;
> > + } else {
> > + mhi_dev->dl_chan = mhi_chan;
> > + mhi_dev->dl_chan_id = mhi_chan->chan;
> > + }
> > +
> > + get_device(&mhi_dev->dev);
> > + mhi_chan->mhi_dev = mhi_dev;
> > +
> > + /* Configure secondary channel as well */
> > + mhi_chan++;
> > + if (mhi_chan->dir == DMA_TO_DEVICE) {
> > + mhi_dev->ul_chan = mhi_chan;
> > + mhi_dev->ul_chan_id = mhi_chan->chan;
> > + } else {
> > + mhi_dev->dl_chan = mhi_chan;
> > + mhi_dev->dl_chan_id = mhi_chan->chan;
> > + }
> > +
> > + get_device(&mhi_dev->dev);
> > + mhi_chan->mhi_dev = mhi_dev;
> > +
> > + /* Channel name is same for both UL and DL */
>
> You could verify the two channels indeed have the
> same name.
>
done.
Thanks,
Mani
next prev parent reply other threads:[~2022-02-03 15:13 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-02 11:35 [PATCH 00/20] Add initial support for MHI endpoint stack Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 01/20] bus: mhi: Move host MHI code to "host" directory Manivannan Sadhasivam
2021-12-07 1:52 ` Hemant Kumar
2022-01-06 0:20 ` Alex Elder
2021-12-02 11:35 ` [PATCH 02/20] bus: mhi: Move common MHI definitions out of host directory Manivannan Sadhasivam
2022-01-06 0:22 ` Alex Elder
2022-02-03 10:29 ` Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 03/20] bus: mhi: Make mhi_state_str[] array static const and move to common.h Manivannan Sadhasivam
2022-01-06 0:22 ` Alex Elder
2022-02-03 10:34 ` Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 04/20] bus: mhi: Cleanup the register definitions used in headers Manivannan Sadhasivam
2022-01-06 0:23 ` Alex Elder
2022-02-03 11:26 ` Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 05/20] bus: mhi: ep: Add support for registering MHI endpoint controllers Manivannan Sadhasivam
2022-01-06 0:26 ` Alex Elder
2022-02-03 14:50 ` Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 06/20] bus: mhi: ep: Add support for registering MHI endpoint client drivers Manivannan Sadhasivam
2022-01-06 0:27 ` Alex Elder
2022-02-03 14:53 ` Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 07/20] bus: mhi: ep: Add support for creating and destroying MHI EP devices Manivannan Sadhasivam
2022-01-06 0:28 ` Alex Elder
2022-02-03 15:13 ` Manivannan Sadhasivam [this message]
2021-12-02 11:35 ` [PATCH 08/20] bus: mhi: ep: Add support for managing MMIO registers Manivannan Sadhasivam
2022-01-06 0:29 ` Alex Elder
2022-02-03 15:55 ` Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 09/20] bus: mhi: ep: Add support for ring management Manivannan Sadhasivam
2022-01-06 0:30 ` Alex Elder
2022-02-04 9:21 ` Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 10/20] bus: mhi: ep: Add support for sending events to the host Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 11/20] bus: mhi: ep: Add support for managing MHI state machine Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 12/20] bus: mhi: ep: Add support for processing MHI endpoint interrupts Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 13/20] bus: mhi: ep: Add support for powering up the MHI endpoint stack Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 14/20] bus: mhi: ep: Add support for powering down " Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 15/20] bus: mhi: ep: Add support for handling MHI_RESET Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 16/20] bus: mhi: ep: Add support for handling SYS_ERR condition Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 17/20] bus: mhi: ep: Add support for processing command and TRE rings Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 18/20] bus: mhi: ep: Add support for queueing SKBs over MHI bus Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 19/20] bus: mhi: ep: Add support for suspending and resuming channels Manivannan Sadhasivam
2021-12-02 11:35 ` [PATCH 20/20] bus: mhi: ep: Add uevent support for module autoloading Manivannan Sadhasivam
2022-01-06 0:20 ` [PATCH 00/20] Add initial support for MHI endpoint stack Alex Elder
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