Re: [PATCH v3] USB: hub: Fix the broken detection of USB3 device in SMSC hub

[Eugeniu Rosca <erosca@de.adit-jv.com>]

Hi Hardik,

On Tue, Feb 04, 2020 at 06:44:13PM +0100, Hardik Gajjar wrote:
> Renesas R-Car H3ULCB + Kingfisher Infotainment Board is either not able
> to detect the USB3.0 mass storage devices or is detecting those as
> USB2.0 high speed devices.
> 
> The explanation given by Renesas is that, due to a HW issue, the XHCI
> driver does not wake up after going to sleep on connecting a USB3.0
> device.
> 
> In order to mitigate that, disable the auto-suspend feature
> specifically for SMSC hubs from hub_probe() function, as a quirk.
> 
> Renesas Kingfisher Infotainment Board has two USB3.0 ports (CN2) which
> are connected via USB5534B 4-port SuperSpeed/Hi-Speed, low-power,
> configurable hub controller.
> 
> [1] SanDisk USB 3.0 device detected as USB-2.0 before the patch
>  [   74.036390] usb 5-1.1: new high-speed USB device number 4 using xhci-hcd
>  [   74.061598] usb 5-1.1: New USB device found, idVendor=0781, idProduct=5581, bcdDevice= 1.00
>  [   74.069976] usb 5-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
>  [   74.077303] usb 5-1.1: Product: Ultra
>  [   74.080980] usb 5-1.1: Manufacturer: SanDisk
>  [   74.085263] usb 5-1.1: SerialNumber: 4C530001110208116550
> 
> [2] SanDisk USB 3.0 device detected as USB-3.0 after the patch
>  [   34.565078] usb 6-1.1: new SuperSpeed Gen 1 USB device number 3 using xhci-hcd
>  [   34.588719] usb 6-1.1: New USB device found, idVendor=0781, idProduct=5581, bcdDevice= 1.00
>  [   34.597098] usb 6-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
>  [   34.604430] usb 6-1.1: Product: Ultra
>  [   34.608110] usb 6-1.1: Manufacturer: SanDisk
>  [   34.612397] usb 6-1.1: SerialNumber: 4C530001110208116550

Thanks for the comprehensible and accurate write-up.

> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> index a9e24e4..2fe9c9f 100644
> --- a/drivers/usb/core/hub.h
> +++ b/drivers/usb/core/hub.h
> @@ -61,6 +61,7 @@ struct usb_hub {
>  	unsigned		quiescing:1;
>  	unsigned		disconnected:1;
>  	unsigned		in_reset:1;
> +	unsigned                quirk_disable_autosuspend:1;

I think it would make sense to respin the patch once again with the
above spaces converted to tabs, for consistency.

I would also include Alan's Acked-by (thanks!) and since Alan reshaped
the patch significantly in the last iteration, I would add his
Suggested-by too.

In addition to the above (please, also include):

Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>

Thanks!

-- 
Best Regards
Eugeniu Rosca