Ping ! >-----Original Message----- >From: Anurag Kumar Vulisha [mailto:anurag.kumar.vulisha@xxxxxxxxxx] >Sent: Friday, February 03, 2017 10:10 PM >To: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>; Mauro Carvalho >Chehab <mchehab@xxxxxxxxxx> >Cc: Punnaiah Choudary Kalluri <punnaia@xxxxxxxxxx>; Anirudha Sarangi ><anirudh@xxxxxxxxxx>; linux-media@xxxxxxxxxxxxxxx; linux- >kernel@xxxxxxxxxxxxxxx; Anurag Kumar Vulisha <anuragku@xxxxxxxxxx> >Subject: [PATCH] media: uvcvideo: Add support for changing >UVC_URBS/UVC_MAX_PACKETS from sysfs > >The uvc_video.c driver currently has fixed the maximum UVC_URBS queued to 5 >and max UVC_MAX_PACKETS per URB to 32K. This configuration works fine with >USB 2.0 and some USB 3.0 cameras on embedded platforms(like Zynq Ultrascale). >Since embedded platforms has slow processing speed as compared to >servers/x86 machines, we may need to increase the number of URBs(UVC_URBS) >queued. Also some next generation USB 3.0 cameras (like ZED stereo camera) >splits each frame into multiple chunks of 48K bytes (which is greater than the size >of UVC_MAX_PACKETS per URB), so we may need to increase >UVC_MAX_PACKETS also at runtime instead of #define it. > >This patch adds the solution to change UVC_URBS and UVC_MAX_PACKETS at >runtime using sysfs layer before starting the video application. > >Signed-off-by: Anurag Kumar Vulisha <anuragku@xxxxxxxxxx> >--- > drivers/media/usb/uvc/uvc_driver.c | 89 >++++++++++++++++++++++++++++++++++++++ > drivers/media/usb/uvc/uvc_video.c | 39 ++++++++++++----- > drivers/media/usb/uvc/uvcvideo.h | 12 +++-- > 3 files changed, 126 insertions(+), 14 deletions(-) > >diff --git a/drivers/media/usb/uvc/uvc_driver.c >b/drivers/media/usb/uvc/uvc_driver.c >index 04bf350..51c8058 100644 >--- a/drivers/media/usb/uvc/uvc_driver.c >+++ b/drivers/media/usb/uvc/uvc_driver.c >@@ -190,6 +190,89 @@ static struct uvc_format_desc uvc_fmts[] = { > }, > }; > >+/* Sysfs attributes for show and store max_urbs/max_packets per URB */ >+ >+static ssize_t get_max_urbs_show(struct device *dev, >+ struct device_attribute *attr, char *buf) { >+ >+ struct uvc_streaming *stream = NULL; >+ struct usb_interface *intf = to_usb_interface(dev); >+ struct uvc_device *udev = usb_get_intfdata(intf); >+ u32 ret_len = 0; >+ u32 stream_num = 0; >+ >+ list_for_each_entry(stream, &udev->streams, list) { >+ ret_len += scnprintf((char *)(buf + ret_len), PAGE_SIZE, >+ "stream[%d] = %d\n", stream_num++, >+ stream->max_urbs); >+ } >+ >+ return ret_len; >+} >+static DEVICE_ATTR_RO(get_max_urbs); >+ >+static ssize_t set_max_urbs_store(struct device *dev, >+ struct device_attribute *attr, const char *buf, size_t count) { >+ >+ struct uvc_streaming *stream; >+ struct usb_interface *intf = to_usb_interface(dev); >+ struct uvc_device *udev = usb_get_intfdata(intf); >+ >+ list_for_each_entry(stream, &udev->streams, list) { >+ sscanf(buf, "%d", &stream->max_urbs); >+ } >+ >+ return count; >+} >+static DEVICE_ATTR_WO(set_max_urbs); >+ >+static ssize_t get_max_packets_show(struct device *dev, >+ struct device_attribute *attr, char *buf) { >+ >+ struct uvc_streaming *stream = NULL; >+ struct usb_interface *intf = to_usb_interface(dev); >+ struct uvc_device *udev = usb_get_intfdata(intf); >+ u32 ret_len = 0; >+ u32 stream_num = 0; >+ >+ list_for_each_entry(stream, &udev->streams, list) { >+ ret_len += scnprintf((char *)(buf + ret_len), PAGE_SIZE, >+ "stream[%d] = %d\n", stream_num++, >+ stream->max_packets); >+ } >+ >+ return ret_len; >+} >+static DEVICE_ATTR_RO(get_max_packets); >+ >+static ssize_t set_max_packets_store(struct device *dev, >+ struct device_attribute *attr, const char *buf, size_t count) { >+ >+ struct uvc_streaming *stream; >+ struct usb_interface *intf = to_usb_interface(dev); >+ struct uvc_device *udev = usb_get_intfdata(intf); >+ >+ list_for_each_entry(stream, &udev->streams, list) { >+ sscanf(buf, "%d", &stream->max_packets); >+ } >+ >+ return count; >+} >+static DEVICE_ATTR_WO(set_max_packets); >+ >+static struct attribute *uvc_attributes[] = { >+ &dev_attr_get_max_urbs.attr, >+ &dev_attr_set_max_urbs.attr, >+ &dev_attr_get_max_packets.attr, >+ &dev_attr_set_max_packets.attr, >+ NULL >+}; >+ >+static const struct attribute_group uvc_attr_group = { >+ .attrs = uvc_attributes, >+}; >+ >+ > /* ------------------------------------------------------------------------ > * Utility functions > */ >@@ -2097,6 +2180,12 @@ static int uvc_probe(struct usb_interface *intf, > "supported.\n", ret); > } > >+ ret = sysfs_create_group(&dev->intf->dev.kobj, &uvc_attr_group); >+ if (ret < 0) { >+ uvc_printk(KERN_ERR, "Failed to create sysfs node %d\n", ret); >+ return ret; >+ } >+ > uvc_trace(UVC_TRACE_PROBE, "UVC device initialized.\n"); > usb_enable_autosuspend(udev); > return 0; >diff --git a/drivers/media/usb/uvc/uvc_video.c >b/drivers/media/usb/uvc/uvc_video.c >index f3c1c85..18efd03 100644 >--- a/drivers/media/usb/uvc/uvc_video.c >+++ b/drivers/media/usb/uvc/uvc_video.c >@@ -1362,7 +1362,7 @@ static void uvc_free_urb_buffers(struct uvc_streaming >*stream) { > unsigned int i; > >- for (i = 0; i < UVC_URBS; ++i) { >+ for (i = 0; i < stream->max_urbs; ++i) { > if (stream->urb_buffer[i]) { > #ifndef CONFIG_DMA_NONCOHERENT > usb_free_coherent(stream->dev->udev, stream- >>urb_size, @@ -1374,6 +1374,11 @@ static void uvc_free_urb_buffers(struct >uvc_streaming *stream) > } > } > >+ /* Free memory used for storing URB pointers */ >+ kfree(stream->urb); >+ kfree(stream->urb_buffer); >+ kfree(stream->urb_dma); >+ > stream->urb_size = 0; > } > >@@ -1382,7 +1387,7 @@ static void uvc_free_urb_buffers(struct uvc_streaming >*stream) > * already allocated when resuming from suspend, in which case it will > * return without touching the buffers. > * >- * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the >+ * Limit the buffer size to stream->max_packets bulk/isochronous >+ packets. If the > * system is too low on memory try successively smaller numbers of packets > * until allocation succeeds. > * >@@ -1398,16 +1403,24 @@ static int uvc_alloc_urb_buffers(struct >uvc_streaming *stream, > if (stream->urb_size) > return stream->urb_size / psize; > >+ /* Allocate memory for storing URB pointers */ >+ stream->urb = (struct urb **)kcalloc(stream->max_urbs, >+ sizeof(struct urb *), gfp_flags | __GFP_NOWARN); >+ stream->urb_buffer = (char **)kcalloc(stream->max_urbs, >+ sizeof(char *), gfp_flags | __GFP_NOWARN); >+ stream->urb_dma = (dma_addr_t *)kcalloc(stream->max_urbs, >+ sizeof(dma_addr_t), gfp_flags | >__GFP_NOWARN); >+ > /* Compute the number of packets. Bulk endpoints might transfer UVC > * payloads across multiple URBs. > */ > npackets = DIV_ROUND_UP(size, psize); >- if (npackets > UVC_MAX_PACKETS) >- npackets = UVC_MAX_PACKETS; >+ if (npackets > stream->max_packets) >+ npackets = stream->max_packets; > > /* Retry allocations until one succeed. */ > for (; npackets > 1; npackets /= 2) { >- for (i = 0; i < UVC_URBS; ++i) { >+ for (i = 0; i < stream->max_urbs; ++i) { > stream->urb_size = psize * npackets; #ifndef >CONFIG_DMA_NONCOHERENT > stream->urb_buffer[i] = usb_alloc_coherent( @@ - >1423,9 +1436,9 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming >*stream, > } > } > >- if (i == UVC_URBS) { >+ if (i == stream->max_urbs) { > uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB >buffers " >- "of %ux%u bytes each.\n", UVC_URBS, >npackets, >+ "of %ux%u bytes each.\n", stream->max_urbs, >npackets, > psize); > return npackets; > } >@@ -1446,7 +1459,7 @@ static void uvc_uninit_video(struct uvc_streaming >*stream, int free_buffers) > > uvc_video_stats_stop(stream); > >- for (i = 0; i < UVC_URBS; ++i) { >+ for (i = 0; i < stream->max_urbs; ++i) { > urb = stream->urb[i]; > if (urb == NULL) > continue; >@@ -1507,7 +1520,7 @@ static int uvc_init_video_isoc(struct uvc_streaming >*stream, > > size = npackets * psize; > >- for (i = 0; i < UVC_URBS; ++i) { >+ for (i = 0; i < stream->max_urbs; ++i) { > urb = usb_alloc_urb(npackets, gfp_flags); > if (urb == NULL) { > uvc_uninit_video(stream, 1); >@@ -1573,7 +1586,7 @@ static int uvc_init_video_bulk(struct uvc_streaming >*stream, > if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) > size = 0; > >- for (i = 0; i < UVC_URBS; ++i) { >+ for (i = 0; i < stream->max_urbs; ++i) { > urb = usb_alloc_urb(0, gfp_flags); > if (urb == NULL) { > uvc_uninit_video(stream, 1); >@@ -1678,7 +1691,7 @@ static int uvc_init_video(struct uvc_streaming *stream, >gfp_t gfp_flags) > return ret; > > /* Submit the URBs. */ >- for (i = 0; i < UVC_URBS; ++i) { >+ for (i = 0; i < stream->max_urbs; ++i) { > ret = usb_submit_urb(stream->urb[i], gfp_flags); > if (ret < 0) { > uvc_printk(KERN_ERR, "Failed to submit URB %u " >@@ -1839,6 +1852,10 @@ int uvc_video_init(struct uvc_streaming *stream) > stream->cur_format = format; > stream->cur_frame = frame; > >+ /* Set max URB numbers & max packets per URB to default */ >+ stream->max_urbs = UVC_URBS; >+ stream->max_packets = UVC_MAX_PACKETS; >+ > /* Select the video decoding function */ > if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) { > if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT) diff --git >a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h >index 3d6cc62..250cf89 100644 >--- a/drivers/media/usb/uvc/uvcvideo.h >+++ b/drivers/media/usb/uvc/uvcvideo.h >@@ -506,9 +506,15 @@ struct uvc_streaming { > __u32 max_payload_size; > } bulk; > >- struct urb *urb[UVC_URBS]; >- char *urb_buffer[UVC_URBS]; >- dma_addr_t urb_dma[UVC_URBS]; >+ /* Maximum number of URBs that can be submitted */ >+ u32 max_urbs; >+ >+ /* Maximum number of packets per URB */ >+ u32 max_packets; >+ >+ struct urb **urb; >+ char **urb_buffer; >+ dma_addr_t *urb_dma; > unsigned int urb_size; > > __u32 sequence; >-- >2.1.1 This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. 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