[PATCH 3.16 055/233] usb: host: xhci-mem: allocate zeroed Scratchpad Buffer

From: Ben Hutchings
Date: Sat Sep 09 2017 - 19:18:09 EST


3.16.48-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Peter Chen <peter.chen@xxxxxxx>

commit 7480d912d549f414e0ce39331870899e89a5598c upstream.

According to xHCI ch4.20 Scratchpad Buffers, the Scratchpad
Buffer needs to be zeroed.

...
The following operations take place to allocate
Scratchpad Buffers to the xHC:
...
b. Software clears the Scratchpad Buffer to '0'

Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-mem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1709,7 +1709,7 @@ static int scratchpad_alloc(struct xhci_
xhci->dcbaa->dev_context_ptrs[0] = cpu_to_le64(xhci->scratchpad->sp_dma);
for (i = 0; i < num_sp; i++) {
dma_addr_t dma;
- void *buf = dma_alloc_coherent(dev, xhci->page_size, &dma,
+ void *buf = dma_zalloc_coherent(dev, xhci->page_size, &dma,
flags);
if (!buf)
goto fail_sp5;