Hi Eddie,
On 04/06/2017 10:14 AM, Marek Vasut wrote:
On 04/06/2017 04:03 AM, Eddie Cai wrote:
We should invalidate the dcache before starting the DMA. In case there are any dirty lines from the DMA buffer in the cache, subsequent cache-line replacements may corrupt the buffer in memory while the DMA is still going on. Cache-line replacement can happen if the CPU tries to bring some other memory locations into the cache while the DMA is going on.
Signed-off-by: Eddie Cai eddie.cai.linux@gmail.com Reviewed-by: Stefan Brüns stefan.bruens@rwth-aachen.de
drivers/usb/host/dwc2.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c index 5ac602e..e3a5d7d 100644 --- a/drivers/usb/host/dwc2.c +++ b/drivers/usb/host/dwc2.c @@ -811,12 +811,19 @@ static int transfer_chunk(struct dwc2_hc_regs *hc_regs, void *aligned_buffer, (*pid << DWC2_HCTSIZ_PID_OFFSET), &hc_regs->hctsiz);
- if (!in && xfer_len) {
memcpy(aligned_buffer, buffer, xfer_len);flush_dcache_range((unsigned long)aligned_buffer,(unsigned long)aligned_buffer +roundup(xfer_len, ARCH_DMA_MINALIGN));
- if (xfer_len) {
if (in) {invalidate_dcache_range((unsigned long)aligned_buffer,(unsigned long)aligned_buffer +Should be uintptr_t all over the place to deal with 32/64 bit systems, otherwise great, thanks.
roundup(xfer_len, ARCH_DMA_MINALIGN));} else {memcpy(aligned_buffer, buffer, xfer_len);flush_dcache_range((unsigned long)aligned_buffer,(unsigned long)aligned_buffer +roundup(xfer_len, ARCH_DMA_MINALIGN));}}
writel(phys_to_bus((unsigned long)aligned_buffer), &hc_regs->hcdma);
Did you test with remove another invalidate_dcache_range() in this function? I still think no need to have 2 invalidate_dcache in this function.
Thanks, - Kever