[U-Boot] [PATCH v2] fastboot: OUT transaction length must be aligned to wMaxPacketSize

[Marek Vasut]

On 04/05/2016 08:31 PM, Steve Rae wrote:
> commit 9e4b510 fastboot: OUT transaction length must be aligned to wMaxPacketSize
> breaks some boards...
> 
> Therefore add a conditional Kconfig to optionally enable this feature.

Did you drill into it to figure out why this is needed ?

> Signed-off-by: Steve Rae <srae at broadcom.com>
> ---
> 
> Changes in v2:
> - ammendment to the original patch
> 
>  drivers/usb/gadget/Kconfig      | 7 +++++++
>  drivers/usb/gadget/f_fastboot.c | 4 +++-
>  2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
> index f4698f4..ab1c605 100644
> --- a/drivers/usb/gadget/Kconfig
> +++ b/drivers/usb/gadget/Kconfig
> @@ -33,3 +33,10 @@ menuconfig USB_GADGET
>  	   a USB peripheral device.  Configure one hardware driver for your
>  	   peripheral/device side bus controller, and a "gadget driver" for
>  	   your peripheral protocol.
> +
> +config USB_GADGET_FASTBOOT_DOWNLOAD_ALIGNMENT_REQUIRED
> +	bool "fastboot download requires alignment with wMaxPacketSize"
> +	help
> +	   By default, the fastboot download OUT transactions are aligned
> +	   to "ep->maxpacket". This option causes the fastboot download OUT
> +	   transactions to be aligned with "wMaxPacketSize".
> diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
> index 2e87fee..130b5d0 100644
> --- a/drivers/usb/gadget/f_fastboot.c
> +++ b/drivers/usb/gadget/f_fastboot.c
> @@ -430,17 +430,19 @@ static void cb_getvar(struct usb_ep *ep, struct usb_request *req)
>  static unsigned int rx_bytes_expected(unsigned int maxpacket)
>  {
>  	int rx_remain = download_size - download_bytes;
> -	int rem = 0;
> +	int __maybe_unused rem = 0;
>  	if (rx_remain < 0)
>  		return 0;
>  	if (rx_remain > EP_BUFFER_SIZE)
>  		return EP_BUFFER_SIZE;
> +#ifdef CONFIG_USB_GADGET_FASTBOOT_DOWNLOAD_ALIGNMENT_REQUIRED
>  	if (rx_remain < maxpacket) {
>  		rx_remain = maxpacket;
>  	} else if (rx_remain % maxpacket != 0) {
>  		rem = rx_remain % maxpacket;
>  		rx_remain = rx_remain + (maxpacket - rem);
>  	}
> +#endif
>  	return rx_remain;
>  }
>  
> 


-- 
Best regards,
Marek Vasut