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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>
This commit is contained in:
Eddie Cai 2017-04-06 11:37:04 +08:00 committed by Marek Vasut
parent 889239d6b5
commit 57ca63b86e
1 changed files with 13 additions and 6 deletions
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19
drivers/usb/host/dwc2.c
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@ -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);