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Date:   Wed, 4 Nov 2020 23:42:01 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Joe Perches <joe@perches.com>
Cc:     Ricardo Ribalda <ribalda@chromium.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/7] media: uvcvideo: Use pr_cont() macro
Message-ID: <20201104214201.GH29958@pendragon.ideasonboard.com>
References: <20201104180734.286789-1-ribalda@chromium.org>
 <20201104180734.286789-2-ribalda@chromium.org>
 <87769d554b4575bf9371380b013e66d70f1b21c4.camel@perches.com>
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In-Reply-To: <87769d554b4575bf9371380b013e66d70f1b21c4.camel@perches.com>
Precedence: bulk

Hi Joe,

On Wed, Nov 04, 2020 at 11:29:30AM -0800, Joe Perches wrote:
> On Wed, 2020-11-04 at 19:07 +0100, Ricardo Ribalda wrote:
> > Replace all the uses of printk(KERN_CONT ... with pr_cont().
> 
> Perhaps remove the uvc_printk macro and uses and use the more
> common pr_fmt and pr_<level> mechanisms.

I'd actually go for dev_* instead, to give some context. It's fairly
common to have multiple UVC devices connected to a system, so printing
the device name would be useful. It can still be wrapped with
uvc_printk() if we want to wrap the cast from uvc_device to a struct
device (we should actually try to get the device corresponding to the
USB interface where available, so we should use uvc_streaming->intf->dev
where possible, and fallback to uvc_device->udev->dev otherwise), or
drop the wrapper completely.

> Something like:
> ---
>  drivers/media/usb/uvc/uvc_ctrl.c   |  5 +++--
>  drivers/media/usb/uvc/uvc_driver.c | 35 +++++++++++++++------------------
>  drivers/media/usb/uvc/uvc_entity.c | 10 ++++++----
>  drivers/media/usb/uvc/uvc_status.c |  9 +++++----
>  drivers/media/usb/uvc/uvc_video.c  | 40 ++++++++++++++++----------------------
>  drivers/media/usb/uvc/uvcvideo.h   | 25 +++++++++++-------------
>  6 files changed, 58 insertions(+), 66 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index f479d8971dfb..e0b273697d49 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -6,6 +6,8 @@
>   *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
>   */
>  
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
>  #include <linux/kernel.h>
>  #include <linux/list.h>
>  #include <linux/module.h>
> @@ -1317,8 +1319,7 @@ static void uvc_ctrl_status_event_work(struct work_struct *work)
>  	w->urb->interval = dev->int_ep->desc.bInterval;
>  	ret = usb_submit_urb(w->urb, GFP_KERNEL);
>  	if (ret < 0)
> -		uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
> -			   ret);
> +		pr_err("Failed to resubmit status URB (%d)\n", ret);
>  }
>  
>  bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index ddb9eaa11be7..03d68e2b6b70 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -6,6 +6,8 @@
>   *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
>   */
>  
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
>  #include <linux/atomic.h>
>  #include <linux/kernel.h>
>  #include <linux/list.h>
> @@ -534,8 +536,7 @@ static int uvc_parse_format(struct uvc_device *dev,
>  				sizeof(format->name));
>  			format->fcc = fmtdesc->fcc;
>  		} else {
> -			uvc_printk(KERN_INFO, "Unknown video format %pUl\n",
> -				&buffer[5]);
> +			pr_info("Unknown video format %pUl\n", &buffer[5]);
>  			snprintf(format->name, sizeof(format->name), "%pUl\n",
>  				&buffer[5]);
>  			format->fcc = 0;
> @@ -1925,7 +1926,7 @@ static int uvc_scan_device(struct uvc_device *dev)
>  		uvc_scan_fallback(dev);
>  
>  	if (list_empty(&dev->chains)) {
> -		uvc_printk(KERN_INFO, "No valid video chain found.\n");
> +		pr_info("No valid video chain found\n");
>  		return -1;
>  	}
>  
> @@ -2077,8 +2078,8 @@ int uvc_register_video_device(struct uvc_device *dev,
>  
>  	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
>  	if (ret < 0) {
> -		uvc_printk(KERN_ERR, "Failed to register %s device (%d).\n",
> -			   v4l2_type_names[type], ret);
> +		pr_err("Failed to register %s device (%d)\n",
> +		       v4l2_type_names[type], ret);
>  		return ret;
>  	}
>  
> @@ -2094,8 +2095,7 @@ static int uvc_register_video(struct uvc_device *dev,
>  	/* Initialize the streaming interface with default parameters. */
>  	ret = uvc_video_init(stream);
>  	if (ret < 0) {
> -		uvc_printk(KERN_ERR, "Failed to initialize the device (%d).\n",
> -			   ret);
> +		pr_err("Failed to initialize the device (%d)\n", ret);
>  		return ret;
>  	}
>  
> @@ -2129,8 +2129,8 @@ static int uvc_register_terms(struct uvc_device *dev,
>  
>  		stream = uvc_stream_by_id(dev, term->id);
>  		if (stream == NULL) {
> -			uvc_printk(KERN_INFO, "No streaming interface found "
> -				   "for terminal %u.", term->id);
> +			pr_info("No streaming interface found for terminal %u\n",
> +				term->id);
>  			continue;
>  		}
>  
> @@ -2163,8 +2163,7 @@ static int uvc_register_chains(struct uvc_device *dev)
>  #ifdef CONFIG_MEDIA_CONTROLLER
>  		ret = uvc_mc_register_entities(chain);
>  		if (ret < 0)
> -			uvc_printk(KERN_INFO,
> -				   "Failed to register entities (%d).\n", ret);
> +			pr_info("Failed to register entities (%d)\n", ret);
>  #endif
>  	}
>  
> @@ -2261,17 +2260,16 @@ static int uvc_probe(struct usb_interface *intf,
>  		goto error;
>  	}
>  
> -	uvc_printk(KERN_INFO, "Found UVC %u.%02x device %s (%04x:%04x)\n",
> +	pr_info("Found UVC %u.%02x device %s (%04x:%04x)\n",
>  		dev->uvc_version >> 8, dev->uvc_version & 0xff,
>  		udev->product ? udev->product : "<unnamed>",
>  		le16_to_cpu(udev->descriptor.idVendor),
>  		le16_to_cpu(udev->descriptor.idProduct));
>  
>  	if (dev->quirks != dev->info->quirks) {
> -		uvc_printk(KERN_INFO, "Forcing device quirks to 0x%x by module "
> -			"parameter for testing purpose.\n", dev->quirks);
> -		uvc_printk(KERN_INFO, "Please report required quirks to the "
> -			"linux-uvc-devel mailing list.\n");
> +		pr_info("Forcing device quirks to 0x%x by module parameter for testing purpose\n",
> +			dev->quirks);
> +		pr_info("Please report required quirks to the linux-uvc-devel mailing list\n");
>  	}
>  
>  	/* Register the V4L2 device. */
> @@ -2300,9 +2298,8 @@ static int uvc_probe(struct usb_interface *intf,
>  
>  	/* Initialize the interrupt URB. */
>  	if ((ret = uvc_status_init(dev)) < 0) {
> -		uvc_printk(KERN_INFO, "Unable to initialize the status "
> -			"endpoint (%d), status interrupt will not be "
> -			"supported.\n", ret);
> +		pr_info("Unable to initialize the status endpoint (%d), status interrupt will not be supported\n",
> +			ret);
>  	}
>  
>  	uvc_trace(UVC_TRACE_PROBE, "UVC device initialized.\n");
> diff --git a/drivers/media/usb/uvc/uvc_entity.c b/drivers/media/usb/uvc/uvc_entity.c
> index ca3a9c2eec27..a5c11cde273c 100644
> --- a/drivers/media/usb/uvc/uvc_entity.c
> +++ b/drivers/media/usb/uvc/uvc_entity.c
> @@ -6,6 +6,8 @@
>   *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
>   */
>  
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
>  #include <linux/kernel.h>
>  #include <linux/list.h>
>  #include <linux/videodev2.h>
> @@ -139,8 +141,8 @@ int uvc_mc_register_entities(struct uvc_video_chain *chain)
>  	list_for_each_entry(entity, &chain->entities, chain) {
>  		ret = uvc_mc_init_entity(chain, entity);
>  		if (ret < 0) {
> -			uvc_printk(KERN_INFO, "Failed to initialize entity for "
> -				   "entity %u\n", entity->id);
> +			pr_info("Failed to initialize entity for entity %u\n",
> +				entity->id);
>  			return ret;
>  		}
>  	}
> @@ -148,8 +150,8 @@ int uvc_mc_register_entities(struct uvc_video_chain *chain)
>  	list_for_each_entry(entity, &chain->entities, chain) {
>  		ret = uvc_mc_create_links(chain, entity);
>  		if (ret < 0) {
> -			uvc_printk(KERN_INFO, "Failed to create links for "
> -				   "entity %u\n", entity->id);
> +			pr_info("Failed to create links for entity %u\n",
> +				entity->id);
>  			return ret;
>  		}
>  	}
> diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
> index 2bdb0ff203f8..4c84525ada71 100644
> --- a/drivers/media/usb/uvc/uvc_status.c
> +++ b/drivers/media/usb/uvc/uvc_status.c
> @@ -6,6 +6,8 @@
>   *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
>   */
>  
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
>  #include <linux/kernel.h>
>  #include <linux/input.h>
>  #include <linux/slab.h>
> @@ -208,8 +210,8 @@ static void uvc_status_complete(struct urb *urb)
>  		return;
>  
>  	default:
> -		uvc_printk(KERN_WARNING, "Non-zero status (%d) in status "
> -			"completion handler.\n", urb->status);
> +		pr_warn("Non-zero status (%d) in status completion handler\n",
> +			urb->status);
>  		return;
>  	}
>  
> @@ -244,8 +246,7 @@ static void uvc_status_complete(struct urb *urb)
>  	/* Resubmit the URB. */
>  	urb->interval = dev->int_ep->desc.bInterval;
>  	if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
> -		uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
> -			ret);
> +		pr_err("Failed to resubmit status URB (%d)\n", ret);
>  	}
>  }
>  
> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
> index a6a441d92b94..6d48bcdeac16 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -6,6 +6,8 @@
>   *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
>   */
>  
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
>  #include <linux/kernel.h>
>  #include <linux/list.h>
>  #include <linux/module.h>
> @@ -76,9 +78,8 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit,
>  	if (likely(ret == size))
>  		return 0;
>  
> -	uvc_printk(KERN_ERR,
> -		   "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n",
> -		   uvc_query_name(query), cs, unit, ret, size);
> +	pr_err("Failed to query (%s) UVC control %u on unit %u: %d (exp. %u)\n",
> +	       uvc_query_name(query), cs, unit, ret, size);
>  
>  	if (ret != -EPIPE)
>  		return ret;
> @@ -254,9 +255,8 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
>  		ret = -EIO;
>  		goto out;
>  	} else if (ret != size) {
> -		uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
> -			"%d (exp. %u).\n", query, probe ? "probe" : "commit",
> -			ret, size);
> +		pr_err("Failed to query (%u) UVC %s control : %d (exp. %u)\n",
> +		       query, probe ? "probe" : "commit", ret, size);
>  		ret = -EIO;
>  		goto out;
>  	}
> @@ -334,9 +334,8 @@ static int uvc_set_video_ctrl(struct uvc_streaming *stream,
>  		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
>  		size, uvc_timeout_param);
>  	if (ret != size) {
> -		uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
> -			"%d (exp. %u).\n", probe ? "probe" : "commit",
> -			ret, size);
> +		pr_err("Failed to set UVC %s control : %d (exp. %u)\n",
> +		       probe ? "probe" : "commit", ret, size);
>  		ret = -EIO;
>  	}
>  
> @@ -1120,8 +1119,7 @@ static void uvc_video_copy_data_work(struct work_struct *work)
>  
>  	ret = usb_submit_urb(uvc_urb->urb, GFP_KERNEL);
>  	if (ret < 0)
> -		uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
> -			   ret);
> +		pr_err("Failed to resubmit video URB (%d)\n", ret);
>  }
>  
>  static void uvc_video_decode_data(struct uvc_urb *uvc_urb,
> @@ -1507,8 +1505,8 @@ static void uvc_video_complete(struct urb *urb)
>  		break;
>  
>  	default:
> -		uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
> -			"completion handler.\n", urb->status);
> +		pr_warn("Non-zero status (%d) in video completion handler\n",
> +			urb->status);
>  		fallthrough;
>  	case -ENOENT:		/* usb_poison_urb() called. */
>  		if (stream->frozen)
> @@ -1545,9 +1543,7 @@ static void uvc_video_complete(struct urb *urb)
>  	if (!uvc_urb->async_operations) {
>  		ret = usb_submit_urb(uvc_urb->urb, GFP_ATOMIC);
>  		if (ret < 0)
> -			uvc_printk(KERN_ERR,
> -				   "Failed to resubmit video URB (%d).\n",
> -				   ret);
> +			pr_err("Failed to resubmit video URB (%d)\n", ret);
>  		return;
>  	}
>  
> @@ -1893,8 +1889,8 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream,
>  	for_each_uvc_urb(uvc_urb, stream) {
>  		ret = usb_submit_urb(uvc_urb->urb, gfp_flags);
>  		if (ret < 0) {
> -			uvc_printk(KERN_ERR, "Failed to submit URB %u (%d).\n",
> -				   uvc_urb_index(uvc_urb), ret);
> +			pr_err("Failed to submit URB %u (%d)\n",
> +			       uvc_urb_index(uvc_urb), ret);
>  			uvc_video_stop_transfer(stream, 1);
>  			return ret;
>  		}
> @@ -1989,7 +1985,7 @@ int uvc_video_init(struct uvc_streaming *stream)
>  	int ret;
>  
>  	if (stream->nformats == 0) {
> -		uvc_printk(KERN_INFO, "No supported video formats found.\n");
> +		pr_info("No supported video formats found\n");
>  		return -EINVAL;
>  	}
>  
> @@ -2029,8 +2025,7 @@ int uvc_video_init(struct uvc_streaming *stream)
>  	}
>  
>  	if (format->nframes == 0) {
> -		uvc_printk(KERN_INFO, "No frame descriptor found for the "
> -			"default format.\n");
> +		pr_info("No frame descriptor found for the default format\n");
>  		return -EINVAL;
>  	}
>  
> @@ -2064,8 +2059,7 @@ int uvc_video_init(struct uvc_streaming *stream)
>  		if (stream->intf->num_altsetting == 1)
>  			stream->decode = uvc_video_encode_bulk;
>  		else {
> -			uvc_printk(KERN_INFO, "Isochronous endpoints are not "
> -				"supported for video output devices.\n");
> +			pr_info("Isochronous endpoints are not supported for video output devices\n");
>  			return -EINVAL;
>  		}
>  	}
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index a3dfacf069c4..724dec20444a 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -725,20 +725,17 @@ extern unsigned int uvc_trace_param;
>  extern unsigned int uvc_timeout_param;
>  extern unsigned int uvc_hw_timestamps_param;
>  
> -#define uvc_trace(flag, msg...) \
> -	do { \
> -		if (uvc_trace_param & flag) \
> -			printk(KERN_DEBUG "uvcvideo: " msg); \
> -	} while (0)
> -
> -#define uvc_warn_once(dev, warn, msg...) \
> -	do { \
> -		if (!test_and_set_bit(warn, &dev->warnings)) \
> -			printk(KERN_INFO "uvcvideo: " msg); \
> -	} while (0)
> -
> -#define uvc_printk(level, msg...) \
> -	printk(level "uvcvideo: " msg)
> +#define uvc_trace(flag, fmt, ...)					\
> +do {									\
> +	if (uvc_trace_param & flag)					\
> +		printk(KERN_DEBUG "uvcvideo: " fmt, ##__VA_ARGS__);	\
> +} while (0)
> +
> +#define uvc_warn_once(dev, warn, fmt, ...)				\
> +do {									\
> +	if (!test_and_set_bit(warn, &(dev)->warnings))			\
> +		pr_info(fmt, ##__VA_ARGS__);				\
> +} while (0)
>  
>  /* --------------------------------------------------------------------------
>   * Internal functions.
> 
> 

-- 
Regards,

Laurent Pinchart