[U-Boot] [RFC PATCH v1] MLK-12883 usb: limit USB_MAX_XFER_BLK to 256

[Peng Fan]

Hi Marcel,

> -----Original Message-----
> From: Marcel Ziswiler [mailto:marcel at ziswiler.com]
> Sent: 2019年2月2日 0:43
> To: u-boot at lists.denx.de
> Cc: Peng Fan <peng.fan at nxp.com>; Marcel Ziswiler
> <marcel.ziswiler at toradex.com>; Masahiro Yamada
> <yamada.masahiro at socionext.com>; Bin Meng <bmeng.cn at gmail.com>;
> Sven Schwermer <sven at svenschwermer.de>
> Subject: [RFC PATCH v1] MLK-12883 usb: limit USB_MAX_XFER_BLK to 256

Thanks for upstreaming this. The MLK-xxx could be dropped, it is NXP internal
tracking number.

Regards,
Peng.

> 
> From: Peng Fan <peng.fan at nxp.com>
> 
> For Some USB mass storage devices, such as:
> "
>  - Kingston DataTraveler 2.0 001D7D06CF09B04199C7B3EA
>  - Class: (from Interface) Mass Storage
>  - PacketSize: 64  Configurations: 1
>  - Vendor: 0x0930  Product 0x6545 Version 1.16 "
> When `usb read 0x80000000 0 0x2000`, we met "EHCI timed out on TD -
> token=0x80008d80".
> 
> The devices does not support scsi VPD page, we are not able to get the
> maximum transfer length for READ(10)/WRITE(10).
> 
> So we limit this to 256 blocks as READ(6).
> 
> Signed-off-by: Peng Fan <peng.fan at nxp.com>
> Acked-by: Marcel Ziswiler <marcel.ziswiler at toradex.com> (cherry picked
> from commit df0052575b2bc9d66ae73584768e1a457ed5d914)
> 
> ---
> This comes from NXP's downstream and has proven to tremendously improve
> the situation with those odd USB mass storage aka memory sticks. This is why
> I post it here asking whether or not this may be something benefiting more
> people. Any feedback and suggestions are welcome.
> 
>  common/usb_storage.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/common/usb_storage.c b/common/usb_storage.c index
> 8c889bb1a6..7420438363 100644
> --- a/common/usb_storage.c
> +++ b/common/usb_storage.c
> @@ -949,7 +949,11 @@ static void usb_stor_set_max_xfer_blk(struct
> usb_device *udev,
>  	 * there is enough free heap space left, but the SCSI READ(10) and
>  	 * WRITE(10) commands are limited to 65535 blocks.
>  	 */
> -	blk = USHRT_MAX;
> +	/*
> +	 * Some USB Massstorage devices have issues, limiting this to 256
> +	 * fixes this.
> +	 */
> +	blk = 256;
>  #else
>  	blk = 20;
>  #endif
> --
> 2.20.1