[PATCH 2/2] usb: hub: increase HUB_DEBOUNCE_TIMEOUT

[Marek Vasut]

On 7/4/22 12:45, Patrick Delaunay wrote:
> Increase HUB_DEBOUNCE_TIMEOUT to 2000 because some usb device
> needs around 1.5s or more to make the hub port status to be
> connected steadily after being powered off and powered on.
> 
> These value is aligned with Linux driver and avoids to configure
> "usb_pgood_delay" as a workaround for connection timeout on
> some USB device; normally the env variable "usb_pgood_delay" is used
> to delay the first query after power ON and thus the device answer,
> but this variable not to increase the connection timeout delay.
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> ---
> Hi,
> 
> I think this patch solves a general issue because a 1s timeout for
> USB connection is too short on problematic USB keys / USB HUB.
> The issue was introduced by the commit c998da0d6709 ("usb: Change
> power-on / scanning timeout handling")
> 
> Patching usb_hub allows to avoid to patch in each board/driver.
> 
> For example, commit 0417169054cb ("imx: ventana: add usb_pgood_delay
> 2sec default") => use pgood_delay = 2s !?
> 
> or ("ARM: stm32: Increase USB power-good delay on DHSOM")
> https://patchwork.ozlabs.org/project/uboot/patch/20211113022444.231801-1-marex@denx.de/
> 
> or commit 2bf352f0c1b7 ("usb: dwc2: Add delay to fix the USB
> detection problem on SoCFPGA") => patch in USB DWC2 driver to add
> a timeout in driver
> 
> The commit 319418c01c95 ("usb: hub: allow pgood_delay to be
> specified via env") introduces an env variable for warm-up times
> managed by hub->query_delay.
> 
> But it is not linked to the connect timeout after power on
> managed by hub->connect_timeout.
> 
> This patch can increase the boot time for some board when USB device is
> not available; if it is a problem I can introduce a new config:
> CONFIG_USB_HUB_DEBOUNCE_TIMEOUT to define this value with default = 1s
> to keep the current behavior.
> 
> This issue appears with DWC2 and USB HUB used in STM32MP135F-DK board;
> pgood_delay=2 is not enough to solved all the USB key detection issues.
> 
> Patrick
> 
> 
>   common/usb_hub.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/common/usb_hub.c b/common/usb_hub.c
> index d73638950b9..e681f1b3073 100644
> --- a/common/usb_hub.c
> +++ b/common/usb_hub.c
> @@ -47,7 +47,7 @@
>   #define HUB_SHORT_RESET_TIME	20
>   #define HUB_LONG_RESET_TIME	200
>   
> -#define HUB_DEBOUNCE_TIMEOUT	1000
> +#define HUB_DEBOUNCE_TIMEOUT	2000

Do you think it is possible to make this somehow dynamic , so not all 
devices would wait so long ?