From 57ca63b86e5987029cd4970890aa28602ba50856 Mon Sep 17 00:00:00 2001
From: Eddie Cai <eddie.cai.linux@gmail.com>
Date: Thu, 6 Apr 2017 11:37:04 +0800
Subject: [PATCH] usb: dwc2: invalidate the dcache before starting the DMA
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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 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);
--
2.39.5