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

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

Hi Neil,

Thank you for the patch.

On ven., juil. 19, 2024 at 15:56, Neil Armstrong <neil.armstrong@linaro.org> wrote:

> 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.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

> ---
>  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