Staging: rspiusb: use NULL virtual address instead of a bogus one

The main problem here is that I just cannot see how this could ever
be correct:

	usb_fill_bulk_urb(pdx->PixelUrb[frameInfo][i], pdx->udev, epAddr,
		(dma_addr_t *) sg_dma_address(&pdx->sgl[frameInfo][i]),
 		sg_dma_len(&pdx->sgl[frameInfo][i]),

You cannot take a DMA address, cast it to a _pointer to_ a DMA address,
and then regard it as a virtual address of the transfer buffer.
However, finding the right virtual address was too hard for me,
so I just stubbed it with NULL. At least usbmon won't oops then
(it will not show any data but it's better than crashing).

Also, too big a buffer was allocated elsewhere.

And since we're at it, drop clearly unnecessary usb_buffer_alloc too,
leaving it where it may be useful.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 10 deletions

diff --git a/drivers/staging/rspiusb/rspiusb.c b/drivers/staging/rspiusb/rspiusb.c
index 1cdfe69585e..2f8155c1968 100644
--- a/drivers/staging/rspiusb/rspiusb.c
+++ b/drivers/staging/rspiusb/rspiusb.c
@@ -444,8 +444,7 @@ static void piusb_write_bulk_callback(struct urb *urb)
                         __func__, status);
 
         pdx->pendingWrite = 0;
-        usb_buffer_free(urb->dev, urb->transfer_buffer_length,
-                        urb->transfer_buffer, urb->transfer_dma);
+        kfree(urb->transfer_buffer);
 }
 
 int piusb_output(struct ioctl_struct *io, unsigned char *uBuf, int len,
@@ -457,9 +456,7 @@ int piusb_output(struct ioctl_struct *io, unsigned char *uBuf, int len,
 
         urb = usb_alloc_urb(0, GFP_KERNEL);
         if (urb != NULL) {
-                kbuf =
-                    usb_buffer_alloc(pdx->udev, len, GFP_KERNEL,
-                                     &urb->transfer_dma);
+                kbuf = kmalloc(len, GFP_KERNEL);
                 if (!kbuf) {
                         dev_err(&pdx->udev->dev, "buffer_alloc failed\n");
                         return -ENOMEM;
@@ -470,7 +467,6 @@ int piusb_output(struct ioctl_struct *io, unsigned char *uBuf, int len,
                 }
                 usb_fill_bulk_urb(urb, pdx->udev, pdx->hEP[io->endpoint], kbuf,
                                   len, piusb_write_bulk_callback, pdx);
-                urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
                 err = usb_submit_urb(urb, GFP_KERNEL);
                 if (err) {
                         dev_err(&pdx->udev->dev,
@@ -641,7 +637,7 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
         numPagesRequired =
             ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
         dbg("Number of pages needed = %d", numPagesRequired);
-        maplist_p = vmalloc(numPagesRequired * sizeof(struct page));
+        maplist_p = vmalloc(numPagesRequired * sizeof(struct page *));
         if (!maplist_p) {
                 dbg("Can't Allocate Memory for maplist_p");
                 return -ENOMEM;
@@ -712,9 +708,7 @@ static int MapUserBuffer(struct ioctl_struct *io, struct device_extension *pdx)
                 usb_fill_bulk_urb(pdx->PixelUrb[frameInfo][i],
                                   pdx->udev,
                                   epAddr,
-                                  (dma_addr_t *) sg_dma_address(&pdx->
-                                                                sgl[frameInfo]
-                                                                [i]),
+                                  NULL, // non-DMA HC? buy a better hardware
                                   sg_dma_len(&pdx->sgl[frameInfo][i]),
                                   piusb_readPIXEL_callback, (void *)pdx);
                 pdx->PixelUrb[frameInfo][i]->transfer_dma =