media: uvcvideo: Refactor URB descriptors

We currently store three separate arrays for each URB reference we hold.

Objectify the data needed to track URBs into a single uvc_urb structure,
allowing better object management and tracking of the URB.

All accesses to the data pointers through stream, are converted to use a
uvc_urb pointer for consistency.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 86a99f461fd8a7b92aee45641c47ccdc05fe85fb..113881bed2a4d87e7e158d808df8b88fdadcbb87 100644 (file)
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1506,14 +1506,16 @@ static void uvc_free_urb_buffers(struct uvc_streaming *stream)
        unsigned int i;
 
        for (i = 0; i < UVC_URBS; ++i) {
-               if (stream->urb_buffer[i]) {
+               struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+
+               if (uvc_urb->buffer) {
 #ifndef CONFIG_DMA_NONCOHERENT
                        usb_free_coherent(stream->dev->udev, stream->urb_size,
-                               stream->urb_buffer[i], stream->urb_dma[i]);
+                                       uvc_urb->buffer, uvc_urb->dma);
 #else
-                       kfree(stream->urb_buffer[i]);
+                       kfree(uvc_urb->buffer);
 #endif
-                       stream->urb_buffer[i] = NULL;
+                       uvc_urb->buffer = NULL;
                }
        }
 
@@ -1551,16 +1553,18 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
        /* Retry allocations until one succeed. */
        for (; npackets > 1; npackets /= 2) {
                for (i = 0; i < UVC_URBS; ++i) {
+                       struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+
                        stream->urb_size = psize * npackets;
 #ifndef CONFIG_DMA_NONCOHERENT
-                       stream->urb_buffer[i] = usb_alloc_coherent(
+                       uvc_urb->buffer = usb_alloc_coherent(
                                stream->dev->udev, stream->urb_size,
-                               gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
+                               gfp_flags | __GFP_NOWARN, &uvc_urb->dma);
 #else
-                       stream->urb_buffer[i] =
+                       uvc_urb->buffer =
                            kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN);
 #endif
-                       if (!stream->urb_buffer[i]) {
+                       if (!uvc_urb->buffer) {
                                uvc_free_urb_buffers(stream);
                                break;
                        }
@@ -1590,13 +1594,15 @@ static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
        uvc_video_stats_stop(stream);
 
        for (i = 0; i < UVC_URBS; ++i) {
-               urb = stream->urb[i];
+               struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+
+               urb = uvc_urb->urb;
                if (urb == NULL)
                        continue;
 
                usb_kill_urb(urb);
                usb_free_urb(urb);
-               stream->urb[i] = NULL;
+               uvc_urb->urb = NULL;
        }
 
        if (free_buffers)
@@ -1651,6 +1657,8 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
        size = npackets * psize;
 
        for (i = 0; i < UVC_URBS; ++i) {
+               struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+
                urb = usb_alloc_urb(npackets, gfp_flags);
                if (urb == NULL) {
                        uvc_uninit_video(stream, 1);
@@ -1663,12 +1671,12 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
                                ep->desc.bEndpointAddress);
 #ifndef CONFIG_DMA_NONCOHERENT
                urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
-               urb->transfer_dma = stream->urb_dma[i];
+               urb->transfer_dma = uvc_urb->dma;
 #else
                urb->transfer_flags = URB_ISO_ASAP;
 #endif
                urb->interval = ep->desc.bInterval;
-               urb->transfer_buffer = stream->urb_buffer[i];
+               urb->transfer_buffer = uvc_urb->buffer;
                urb->complete = uvc_video_complete;
                urb->number_of_packets = npackets;
                urb->transfer_buffer_length = size;
@@ -1678,7 +1686,7 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
                        urb->iso_frame_desc[j].length = psize;
                }
 
-               stream->urb[i] = urb;
+               uvc_urb->urb = urb;
        }
 
        return 0;
@@ -1717,21 +1725,22 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
                size = 0;
 
        for (i = 0; i < UVC_URBS; ++i) {
+               struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+
                urb = usb_alloc_urb(0, gfp_flags);
                if (urb == NULL) {
                        uvc_uninit_video(stream, 1);
                        return -ENOMEM;
                }
 
-               usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
-                       stream->urb_buffer[i], size, uvc_video_complete,
-                       stream);
+               usb_fill_bulk_urb(urb, stream->dev->udev, pipe, uvc_urb->buffer,
+                                 size, uvc_video_complete, stream);
 #ifndef CONFIG_DMA_NONCOHERENT
                urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
-               urb->transfer_dma = stream->urb_dma[i];
+               urb->transfer_dma = uvc_urb->dma;
 #endif
 
-               stream->urb[i] = urb;
+               uvc_urb->urb = urb;
        }
 
        return 0;
@@ -1822,7 +1831,9 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
 
        /* Submit the URBs. */
        for (i = 0; i < UVC_URBS; ++i) {
-               ret = usb_submit_urb(stream->urb[i], gfp_flags);
+               struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+
+               ret = usb_submit_urb(uvc_urb->urb, gfp_flags);
                if (ret < 0) {
                        uvc_printk(KERN_ERR, "Failed to submit URB %u "
                                        "(%d).\n", i, ret);

diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 2b4bb13d4d1dc2615bf287a2114830ef4dabfd9d..81f29b9e4118b004ad2f546673ef1d2c4a362497 100644 (file)
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -490,6 +490,20 @@ struct uvc_stats_stream {
 
 #define UVC_METATADA_BUF_SIZE 1024
 
+/**
+ * struct uvc_urb - URB context management structure
+ *
+ * @urb: the URB described by this context structure
+ * @buffer: memory storage for the URB
+ * @dma: DMA coherent addressing for the urb_buffer
+ */
+struct uvc_urb {
+       struct urb *urb;
+
+       char *buffer;
+       dma_addr_t dma;
+};
+
 struct uvc_streaming {
        struct list_head list;
        struct uvc_device *dev;
@@ -538,9 +552,7 @@ 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];
+       struct uvc_urb uvc_urb[UVC_URBS];
        unsigned int urb_size;
 
        u32 sequence;