USB: cdc-wdm: no need to use usb_alloc_coherent
As Documentation/usb/dma.txt states:
Most drivers should *NOT* be using these primitives; they don't need
to use this type of memory (dma-coherent), and memory returned from
kmalloc() will work just fine.
This driver handle only very low bandwith transfers. It is not an
obvious candidate for usb_alloc_coherent().
Using these calls only serves to complicate the code for no gain,
as has been shown by multiple bugs related to this allocation path.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 846dfa6..8909058 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -256,14 +256,8 @@
static void cleanup(struct wdm_device *desc)
{
- usb_free_coherent(interface_to_usbdev(desc->intf),
- desc->wMaxPacketSize,
- desc->sbuf,
- desc->validity->transfer_dma);
- usb_free_coherent(interface_to_usbdev(desc->intf),
- desc->bMaxPacketSize0,
- desc->inbuf,
- desc->response->transfer_dma);
+ kfree(desc->sbuf);
+ kfree(desc->inbuf);
kfree(desc->orq);
kfree(desc->irq);
kfree(desc->ubuf);
@@ -688,19 +682,13 @@
if (!desc->ubuf)
goto err;
- desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
- desc->wMaxPacketSize,
- GFP_KERNEL,
- &desc->validity->transfer_dma);
+ desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
if (!desc->sbuf)
goto err;
- desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
- desc->wMaxCommand,
- GFP_KERNEL,
- &desc->response->transfer_dma);
+ desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
if (!desc->inbuf)
- goto err2;
+ goto err;
usb_fill_int_urb(
desc->validity,
@@ -712,7 +700,6 @@
desc,
ep->bInterval
);
- desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
@@ -731,30 +718,22 @@
wdm_in_callback,
desc
);
- desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
usb_set_intfdata(intf, desc);
rv = usb_register_dev(intf, &wdm_class);
if (rv < 0)
- goto err3;
+ goto err2;
else
dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
intf->minor - WDM_MINOR_BASE);
out:
return rv;
-err3:
- usb_set_intfdata(intf, NULL);
- usb_free_coherent(interface_to_usbdev(desc->intf),
- desc->bMaxPacketSize0,
- desc->inbuf,
- desc->response->transfer_dma);
err2:
- usb_free_coherent(interface_to_usbdev(desc->intf),
- desc->wMaxPacketSize,
- desc->sbuf,
- desc->validity->transfer_dma);
+ usb_set_intfdata(intf, NULL);
err:
free_urbs(desc);
+ kfree(desc->inbuf);
+ kfree(desc->sbuf);
kfree(desc->ubuf);
kfree(desc->orq);
kfree(desc->irq);