xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

usb: dwc2: handle DMA buffer unmapping sanely

Browse Source 
The driver's handling of DMA buffers for non-aligned transfers
was kind of nuts. For IN transfers, it left the URB DMA buffer
mapped until the transfer completed, then synced it, copied the
data from the bounce buffer, then synced it again.

Instead of that, just call usb_hcd_unmap_urb_for_dma() to unmap
the buffer before starting the transfer. Then no syncing is
required when doing the copy. This should also allow handling of
other types of mappings besides just dma_map_single() ones.

Also reduce the size of the bounce buffer allocation for Isoc
endpoints to 3K, since that's the largest possible transfer size.

Tested on Raspberry Pi and Altera SOCFPGA.

Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Paul Zimmerman
2014-09-16 13:47:27 -07:00
committed by Greg Kroah-Hartman
parent e8f8c14d9d
commit 5dce95554a
4 changed files with 36 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/usb/dwc2/hcd_queue.c
View File

@@ -229,19 +229,11 @@ static struct dwc2_qh *dwc2_hcd_qh_create(struct dwc2_hsotg *hsotg,
*/
void dwc2_hcd_qh_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
{
u32 buf_size;
if (hsotg->core_params->dma_desc_enable > 0) {
if (hsotg->core_params->dma_desc_enable > 0)
dwc2_hcd_qh_free_ddma(hsotg, qh);
} else if (qh->dw_align_buf) {
if (qh->ep_type == USB_ENDPOINT_XFER_ISOC)
buf_size = 4096;
else
buf_size = hsotg->core_params->max_transfer_size;
dma_free_coherent(hsotg->dev, buf_size, qh->dw_align_buf,
qh->dw_align_buf_dma);
}
else if (qh->dw_align_buf)
dma_free_coherent(hsotg->dev, qh->dw_align_buf_size,
qh->dw_align_buf, qh->dw_align_buf_dma);
kfree(qh);
}