From: Alex Elder <elder@linaro.org>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
mhi@lists.linux.dev
Cc: quic_hemantk@quicinc.com, quic_bbhatt@quicinc.com,
quic_jhugo@quicinc.com, vinod.koul@linaro.org,
bjorn.andersson@linaro.org, dmitry.baryshkov@linaro.org,
quic_vbadigan@quicinc.com, quic_cang@quicinc.com,
quic_skananth@quicinc.com, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 10/25] bus: mhi: ep: Add support for creating and destroying MHI EP devices
Date: Tue, 15 Feb 2022 14:02:57 -0600 [thread overview]
Message-ID: <1cdd8e0c-85d7-dd91-a6f1-1390e7854350@linaro.org> (raw)
In-Reply-To: <20220212182117.49438-11-manivannan.sadhasivam@linaro.org>
On 2/12/22 12:21 PM, 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>
A few comments again, nothing major.
-Alex
> ---
> drivers/bus/mhi/ep/main.c | 77 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 77 insertions(+)
>
> diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
> index f66404181972..fcaacf9ddbd1 100644
> --- a/drivers/bus/mhi/ep/main.c
> +++ b/drivers/bus/mhi/ep/main.c
> @@ -67,6 +67,83 @@ static struct mhi_ep_device *mhi_ep_alloc_device(struct mhi_ep_cntrl *mhi_cntrl,
> return mhi_dev;
> }
>
> +/*
> + * MHI channels are always defined in pairs with UL as the even numbered
> + * channel and DL as odd numbered one.
> + */
Awesome comment. And it seems that the channel ID passed
here is even, and that there *must* be a second mhi_chan[]
entry after the one specified. And UL is also called the
"primary" channel.
> +static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id)
> +{
> + struct mhi_ep_chan *mhi_chan = &mhi_cntrl->mhi_chan[ch_id];
> + struct mhi_ep_device *mhi_dev;
> + int ret;
> +
> + /* Check if the channel name is same for both UL and DL */
> + if (strcmp(mhi_chan->name, mhi_chan[1].name))
> + return -EINVAL;
Maybe log an error to say what's wrong with it?
> +
> + mhi_dev = mhi_ep_alloc_device(mhi_cntrl, MHI_DEVICE_XFER);
> + if (IS_ERR(mhi_dev))
> + return PTR_ERR(mhi_dev);
It looks like the only possible error is no memory, so you could
just have mhi_ep_alloc_device() return NULL.
> +
> + /* Configure primary channel */
> + mhi_dev->ul_chan = mhi_chan;
> + get_device(&mhi_dev->dev);
> + mhi_chan->mhi_dev = mhi_dev;
> +
> + /* Configure secondary channel as well */
> + mhi_chan++;
> + mhi_dev->dl_chan = mhi_chan;
> + get_device(&mhi_dev->dev);
> + mhi_chan->mhi_dev = mhi_dev;
> +
> + /* Channel name is same for both UL and DL */
> + mhi_dev->name = mhi_chan->name;
> + dev_set_name(&mhi_dev->dev, "%s_%s",
> + dev_name(&mhi_cntrl->mhi_dev->dev),
> + mhi_dev->name);
> +
> + ret = device_add(&mhi_dev->dev);
> + if (ret)
> + put_device(&mhi_dev->dev);
> +
> + return ret;
> +}
> +
> +static int mhi_ep_destroy_device(struct device *dev, void *data)
> +{
> + struct mhi_ep_device *mhi_dev;
> + struct mhi_ep_cntrl *mhi_cntrl;
> + struct mhi_ep_chan *ul_chan, *dl_chan;
> +
> + if (dev->bus != &mhi_ep_bus_type)
> + return 0;
> +
> + mhi_dev = to_mhi_ep_device(dev);
> + mhi_cntrl = mhi_dev->mhi_cntrl;
> +
> + /* Only destroy devices created for channels */
> + if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
> + return 0;
> +
> + ul_chan = mhi_dev->ul_chan;
> + dl_chan = mhi_dev->dl_chan;
Aren't they required to supply *both* channels? Or maybe
it's just required that there are transfer callback functions
for both channels. Anyway, no need to check for null, because
the creation function guarantees they're both non-null I think.
> + if (ul_chan)
> + put_device(&ul_chan->mhi_dev->dev);
> +
> + if (dl_chan)
> + put_device(&dl_chan->mhi_dev->dev);
> +
> + dev_dbg(&mhi_cntrl->mhi_dev->dev, "Destroying device for chan:%s\n",
> + mhi_dev->name);
> +
> + /* Notify the client and remove the device from MHI bus */
> + device_del(dev);
> + put_device(dev);
> +
> + return 0;
> +}
> +
> static int parse_ch_cfg(struct mhi_ep_cntrl *mhi_cntrl,
> const struct mhi_ep_cntrl_config *config)
> {
next prev parent reply other threads:[~2022-02-15 20:03 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-12 18:20 [PATCH v3 00/25] Add initial support for MHI endpoint stack Manivannan Sadhasivam
2022-02-12 18:20 ` [PATCH v3 01/25] bus: mhi: Fix pm_state conversion to string Manivannan Sadhasivam
2022-02-15 20:01 ` Alex Elder
2022-02-16 11:33 ` Manivannan Sadhasivam
2022-02-16 13:41 ` Alex Elder
2022-02-12 18:20 ` [PATCH v3 02/25] bus: mhi: Fix MHI DMA structure endianness Manivannan Sadhasivam
2022-02-15 20:02 ` Alex Elder
2022-02-16 7:04 ` Manivannan Sadhasivam
2022-02-16 14:29 ` Alex Elder
2022-02-12 18:20 ` [PATCH v3 03/25] bus: mhi: Move host MHI code to "host" directory Manivannan Sadhasivam
2022-02-15 20:02 ` Alex Elder
2022-02-12 18:20 ` [PATCH v3 04/25] bus: mhi: Move common MHI definitions out of host directory Manivannan Sadhasivam
2022-02-15 0:28 ` Hemant Kumar
2022-02-15 20:02 ` Alex Elder
2022-02-12 18:20 ` [PATCH v3 05/25] bus: mhi: Make mhi_state_str[] array static inline and move to common.h Manivannan Sadhasivam
2022-02-15 0:31 ` Hemant Kumar
2022-02-15 20:02 ` Alex Elder
2022-02-16 11:39 ` Manivannan Sadhasivam
2022-02-16 14:30 ` Alex Elder
2022-02-12 18:20 ` [PATCH v3 06/25] bus: mhi: Cleanup the register definitions used in headers Manivannan Sadhasivam
2022-02-15 0:37 ` Hemant Kumar
2022-02-15 20:02 ` Alex Elder
2022-02-16 17:21 ` Manivannan Sadhasivam
2022-02-16 17:43 ` Manivannan Sadhasivam
2022-02-12 18:20 ` [PATCH v3 07/25] bus: mhi: Get rid of SHIFT macros and use bitfield operations Manivannan Sadhasivam
2022-02-15 20:02 ` Alex Elder
2022-02-16 16:45 ` Manivannan Sadhasivam
2022-02-12 18:21 ` [PATCH v3 08/25] bus: mhi: ep: Add support for registering MHI endpoint controllers Manivannan Sadhasivam
2022-02-15 1:04 ` Hemant Kumar
2022-02-16 17:33 ` Manivannan Sadhasivam
2022-02-15 20:02 ` Alex Elder
2022-02-17 9:53 ` Manivannan Sadhasivam
2022-02-17 14:47 ` Alex Elder
2022-03-04 21:46 ` Jeffrey Hugo
2022-02-12 18:21 ` [PATCH v3 09/25] bus: mhi: ep: Add support for registering MHI endpoint client drivers Manivannan Sadhasivam
2022-02-12 18:32 ` Manivannan Sadhasivam
2022-02-15 1:10 ` Hemant Kumar
2022-02-15 20:02 ` Alex Elder
2022-02-17 10:20 ` Manivannan Sadhasivam
2022-02-17 14:50 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 10/25] bus: mhi: ep: Add support for creating and destroying MHI EP devices Manivannan Sadhasivam
2022-02-15 20:02 ` Alex Elder [this message]
2022-02-17 12:04 ` Manivannan Sadhasivam
2022-02-12 18:21 ` [PATCH v3 11/25] bus: mhi: ep: Add support for managing MMIO registers Manivannan Sadhasivam
2022-02-15 1:14 ` Hemant Kumar
2022-02-15 20:03 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 12/25] bus: mhi: ep: Add support for ring management Manivannan Sadhasivam
2022-02-15 20:03 ` Alex Elder
2022-02-18 8:07 ` Manivannan Sadhasivam
2022-02-18 15:23 ` Manivannan Sadhasivam
2022-02-18 15:47 ` Alex Elder
2022-02-18 15:39 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 13/25] bus: mhi: ep: Add support for sending events to the host Manivannan Sadhasivam
2022-02-15 22:39 ` Alex Elder
2022-02-22 6:06 ` Manivannan Sadhasivam
2022-02-22 13:41 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 14/25] bus: mhi: ep: Add support for managing MHI state machine Manivannan Sadhasivam
2022-02-15 22:39 ` Alex Elder
2022-02-22 7:03 ` Manivannan Sadhasivam
2022-02-12 18:21 ` [PATCH v3 15/25] bus: mhi: ep: Add support for processing MHI endpoint interrupts Manivannan Sadhasivam
2022-02-15 22:39 ` Alex Elder
2022-02-22 8:18 ` Manivannan Sadhasivam
2022-02-22 14:08 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 16/25] bus: mhi: ep: Add support for powering up the MHI endpoint stack Manivannan Sadhasivam
2022-02-15 22:39 ` Alex Elder
2022-02-22 9:08 ` Manivannan Sadhasivam
2022-02-22 14:10 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 17/25] bus: mhi: ep: Add support for powering down " Manivannan Sadhasivam
2022-02-15 22:39 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 18/25] bus: mhi: ep: Add support for handling MHI_RESET Manivannan Sadhasivam
2022-02-15 22:39 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 19/25] bus: mhi: ep: Add support for handling SYS_ERR condition Manivannan Sadhasivam
2022-02-15 22:39 ` Alex Elder
2022-02-22 10:29 ` Manivannan Sadhasivam
2022-02-12 18:21 ` [PATCH v3 20/25] bus: mhi: ep: Add support for processing command ring Manivannan Sadhasivam
2022-02-15 22:40 ` Alex Elder
2022-02-22 10:35 ` Manivannan Sadhasivam
2022-02-12 18:21 ` [PATCH v3 21/25] bus: mhi: ep: Add support for reading from the host Manivannan Sadhasivam
2022-02-15 22:40 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 22/25] bus: mhi: ep: Add support for processing transfer ring Manivannan Sadhasivam
2022-02-15 22:40 ` Alex Elder
2022-02-22 10:50 ` Manivannan Sadhasivam
2022-02-12 18:21 ` [PATCH v3 23/25] bus: mhi: ep: Add support for queueing SKBs to the host Manivannan Sadhasivam
2022-02-15 22:40 ` Alex Elder
2022-02-22 14:38 ` Manivannan Sadhasivam
2022-02-22 15:18 ` Alex Elder
2022-02-22 16:05 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 24/25] bus: mhi: ep: Add support for suspending and resuming channels Manivannan Sadhasivam
2022-02-15 22:40 ` Alex Elder
2022-02-12 18:21 ` [PATCH v3 25/25] bus: mhi: ep: Add uevent support for module autoloading Manivannan Sadhasivam
2022-02-15 22:40 ` Alex Elder
2022-02-15 20:01 ` [PATCH v3 00/25] Add initial support for MHI endpoint stack Alex Elder
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