From: Jie Deng <jie.deng@intel.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-i2c@vger.kernel.org,
virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, wsa@kernel.org,
wsa+renesas@sang-engineering.com, mst@redhat.com, arnd@arndb.de,
jasowang@redhat.com, yu1.wang@intel.com, shuo.a.liu@intel.com,
conghui.chen@intel.com, viresh.kumar@linaro.org,
stefanha@redhat.com
Subject: Re: [PATCH v12] i2c: virtio: add a virtio i2c frontend driver
Date: Mon, 5 Jul 2021 11:46:41 +0800 [thread overview]
Message-ID: <2cb3e0db-f24b-bd12-c1a0-3fc7516b38c5@intel.com> (raw)
In-Reply-To: <YN7jOm68fUL4UA2Q@smile.fi.intel.com>
On 2021/7/2 17:58, Andy Shevchenko wrote:
> On Fri, Jul 02, 2021 at 04:46:47PM +0800, Jie Deng wrote:
>> Add an I2C bus driver for virtio para-virtualization.
>>
>> The controller can be emulated by the backend driver in
>> any device model software by following the virtio protocol.
>>
>> The device specification can be found on
>> https://lists.oasis-open.org/archives/virtio-comment/202101/msg00008.html.
>>
>> By following the specification, people may implement different
>> backend drivers to emulate different controllers according to
>> their needs.
> ...
>
>> +static int virtio_i2c_complete_reqs(struct virtqueue *vq,
>> + struct virtio_i2c_req *reqs,
>> + struct i2c_msg *msgs, int nr,
>> + bool fail)
>> +{
>> + struct virtio_i2c_req *req;
>> + bool failed = fail;
>> + unsigned int len;
>> + int i, j = 0;
>> +
>> + for (i = 0; i < nr; i++) {
>> + /* Detach the ith request from the vq */
>> + req = virtqueue_get_buf(vq, &len);
>> +
>> + /*
>> + * Condition (req && req == &reqs[i]) should always meet since
>> + * we have total nr requests in the vq.
>> + */
>> + if (!failed && (WARN_ON(!(req && req == &reqs[i])) ||
>> + (req->in_hdr.status != VIRTIO_I2C_MSG_OK)))
>> + failed = true;
> ...and after failed is true, we are continuing the loop, why?
Still need to continue to do some cleanup.
>
>> + i2c_put_dma_safe_msg_buf(reqs[i].buf, &msgs[i], !failed);
>> + if (!failed)
>> + ++j;
> Besides better to read j++ the j itself can be renamed to something more
> verbose.
Will change it to j++.
>> + }
>> + return (fail ? -ETIMEDOUT : j);
> Redundant parentheses.
Will remove the parentheses.
>
>> +}
> ...
>
>> + ret = virtio_i2c_send_reqs(vq, reqs, msgs, num);
>> + if (ret != num) {
>> + virtio_i2c_complete_reqs(vq, reqs, msgs, ret, true);
> Below you check the returned code, here is not.
I will do some optimization here.
>
>> + ret = 0;
>> + goto err_free;
>> + }
>> +
>> + reinit_completion(&vi->completion);
>> + virtqueue_kick(vq);
>> +
>> + time_left = wait_for_completion_timeout(&vi->completion, adap->timeout);
>> + if (!time_left)
>> + dev_err(&adap->dev, "virtio i2c backend timeout.\n");
>> +
>> + ret = virtio_i2c_complete_reqs(vq, reqs, msgs, num, !time_left);
>> +
>> +err_free:
>> + kfree(reqs);
>> + return ret;
>> +++ b/include/uapi/linux/virtio_i2c.h
>> +#include <linux/types.h>
>> +
>> +/* The bit 0 of the @virtio_i2c_out_hdr.@flags, used to group the requests */
>> +#define VIRTIO_I2C_FLAGS_FAIL_NEXT BIT(0)
> It's _BITUL() or so from linux/const.h.
> https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/const.h#L28
> You may not use internal definitions in UAPI headers.
Let's use this _BITUL() from linux/const.h instead. Thank you !
next prev parent reply other threads:[~2021-07-05 3:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-02 8:46 [PATCH v12] i2c: virtio: add a virtio i2c frontend driver Jie Deng
2021-07-02 9:58 ` Andy Shevchenko
2021-07-02 23:01 ` Wolfram Sang
2021-07-05 2:43 ` Viresh Kumar
2021-07-05 3:01 ` Jie Deng
2021-07-05 6:21 ` Jie Deng
2021-07-05 6:31 ` Viresh Kumar
2021-07-05 3:46 ` Jie Deng [this message]
2021-07-05 2:40 ` Viresh Kumar
2021-07-05 3:45 ` Jie Deng
2021-07-05 4:38 ` Viresh Kumar
2021-07-05 6:22 ` Jie Deng
2021-07-05 6:30 ` Viresh Kumar
2021-07-05 7:13 ` Jie Deng
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