From 57ca63b86e5987029cd4970890aa28602ba50856 Mon Sep 17 00:00:00 2001 From: Eddie Cai Date: Thu, 6 Apr 2017 11:37:04 +0800 Subject: [PATCH] usb: dwc2: invalidate the dcache before starting the DMA MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Stefan Brüns --- 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 ae7d8fb1da..0e5df15a0d 100644 --- a/drivers/usb/host/dwc2.c +++ b/drivers/usb/host/dwc2.c @@ -817,12 +817,19 @@ 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( + (uintptr_t)aligned_buffer, + (uintptr_t)aligned_buffer + + roundup(xfer_len, ARCH_DMA_MINALIGN)); + } else { + memcpy(aligned_buffer, buffer, xfer_len); + flush_dcache_range( + (uintptr_t)aligned_buffer, + (uintptr_t)aligned_buffer + + roundup(xfer_len, ARCH_DMA_MINALIGN)); + } } writel(phys_to_bus((unsigned long)aligned_buffer), &hc_regs->hcdma); -- 2.25.1