Platforms without hardware coherency can benefit a lot
from using non-coherent buffers. Moreover, platforms
with hardware coherency aren't impacted by this change.
For instance, on AM335x, while it's still not possible
to capture full resolution frames, this patch enables
half-resolution frame streams to work.
Signed-off-by: Ezequiel Garcia <ezequ...@collabora.com>
---
drivers/media/usb/stk1160/stk1160-video.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/drivers/media/usb/stk1160/stk1160-video.c
b/drivers/media/usb/stk1160/stk1160-video.c
index 2811f612820f..aeb4264d1998 100644
--- a/drivers/media/usb/stk1160/stk1160-video.c
+++ b/drivers/media/usb/stk1160/stk1160-video.c
@@ -240,6 +240,9 @@ static void stk1160_process_isoc(struct stk1160 *dev,
struct urb *urb)
return;
}
+ dma_sync_single_for_cpu(&urb->dev->dev, urb->transfer_dma,
+ urb->transfer_buffer_length, DMA_FROM_DEVICE);
+
for (i = 0; i < urb->number_of_packets; i++) {
status = urb->iso_frame_desc[i].status;
if (status < 0) {
@@ -379,16 +382,11 @@ void stk1160_free_isoc(struct stk1160 *dev)
urb = dev->isoc_ctl.urb[i];
if (urb) {
- if (dev->isoc_ctl.transfer_buffer[i]) {
-#ifndef CONFIG_DMA_NONCOHERENT
- usb_free_coherent(dev->udev,
+ if (dev->isoc_ctl.transfer_buffer[i])
+ usb_free_noncoherent(dev->udev,
urb->transfer_buffer_length,
dev->isoc_ctl.transfer_buffer[i],
urb->transfer_dma);
-#else
- kfree(dev->isoc_ctl.transfer_buffer[i]);
-#endif
- }
usb_free_urb(urb);
dev->isoc_ctl.urb[i] = NULL;
}
@@ -461,12 +459,8 @@ int stk1160_alloc_isoc(struct stk1160 *dev)
goto free_i_bufs;
dev->isoc_ctl.urb[i] = urb;
-#ifndef CONFIG_DMA_NONCOHERENT
- dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(dev->udev,
+ dev->isoc_ctl.transfer_buffer[i] =
usb_alloc_noncoherent(dev->udev,
sb_size, GFP_KERNEL, &urb->transfer_dma);
-#else
- dev->isoc_ctl.transfer_buffer[i] = kmalloc(sb_size, GFP_KERNEL);
-#endif
if (!dev->isoc_ctl.transfer_buffer[i]) {
stk1160_err("cannot alloc %d bytes for tx[%d] buffer\n",
sb_size, i);
@@ -490,11 +484,7 @@ int stk1160_alloc_isoc(struct stk1160 *dev)
urb->interval = 1;
urb->start_frame = 0;
urb->number_of_packets = max_packets;
-#ifndef CONFIG_DMA_NONCOHERENT
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
-#else
- urb->transfer_flags = URB_ISO_ASAP;
-#endif
k = 0;
for (j = 0; j < max_packets; j++) {
--
2.18.0
