[PATCH v2 2/3] usb: dwc3: fix dcache flush range calculation

[Neil Armstrong]

The current flush operation will omit doing a flush/invalidate on
the first and last bytes if the base address and size are not aligned
with DMA_MINALIGN.

This causes operation failures Qualcomm platforms.

Take in account the alignment and size of the buffer and also
flush the previous and last cacheline.

Reviewed-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
Signed-off-by: Neil Armstrong <neil.armstrong at linaro.org>
---
 drivers/usb/dwc3/io.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/io.h b/drivers/usb/dwc3/io.h
index 04791d4c9be..1aaf5413c6d 100644
--- a/drivers/usb/dwc3/io.h
+++ b/drivers/usb/dwc3/io.h
@@ -50,6 +50,9 @@ static inline void dwc3_writel(void __iomem *base, u32 offset, u32 value)
 
 static inline void dwc3_flush_cache(uintptr_t addr, int length)
 {
-	flush_dcache_range(addr, addr + ROUND(length, CACHELINE_SIZE));
+	uintptr_t start_addr = (uintptr_t)addr & ~(ARCH_DMA_MINALIGN - 1);
+	uintptr_t end_addr = ALIGN((uintptr_t)addr + length, ARCH_DMA_MINALIGN);
+
+	flush_dcache_range(start_addr, end_addr);
 }
 #endif /* __DRIVERS_USB_DWC3_IO_H */

-- 
2.34.1