[U-Boot,2/2] usb: hub: remove CONFIG_USB_HUB_MIN_POWER_ON_DELAY

From: Stephen Warren <swarren@nvidia.com>

Now that we wait the correct specification-mandated time at the end of
usb_hub_power_on(), I suspect that CONFIG_USB_HUB_MIN_POWER_ON_DELAY has
no purpose.

For cm_t35.h, we already wait longer than the original MIN_POWER_ON_DELAY,
so this change is safe.

For gw_ventana.h, we will wait as long as the original MIN_POWER_ON_DELAY
iff pgood_delay was at least 200ms. I'm not sure if this is the case or
not, hence I've CC'd relevant people to test this change.

Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
 README                       | 3 ---
 common/usb_hub.c             | 6 +-----
 include/configs/cm_t35.h     | 2 --
 include/configs/gw_ventana.h | 1 -
 4 files changed, 1 insertion(+), 11 deletions(-)

On Mon, May 19, 2014 at 1:21 PM, Stephen Warren <swarren@wwwdotorg.org> wrote:
> From: Stephen Warren <swarren@nvidia.com>
>
> Now that we wait the correct specification-mandated time at the end of
> usb_hub_power_on(), I suspect that CONFIG_USB_HUB_MIN_POWER_ON_DELAY has
> no purpose.
>
> For cm_t35.h, we already wait longer than the original MIN_POWER_ON_DELAY,
> so this change is safe.
>
> For gw_ventana.h, we will wait as long as the original MIN_POWER_ON_DELAY
> iff pgood_delay was at least 200ms. I'm not sure if this is the case or
> not, hence I've CC'd relevant people to test this change.
>
> Cc: Igor Grinberg <grinberg@compulab.co.il>
> Cc: Tim Harvey <tharvey@gateworks.com>
> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> ---
>  README                       | 3 ---
>  common/usb_hub.c             | 6 +-----
>  include/configs/cm_t35.h     | 2 --
>  include/configs/gw_ventana.h | 1 -
>  4 files changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/README b/README
> index d8fcd95f9423..091897227c52 100644
> --- a/README
> +++ b/README
> @@ -1432,9 +1432,6 @@ The following options need to be configured:
>                 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
>                 txfilltuning field in the EHCI controller on reset.
>
> -               CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
> -               interval for usb hub power-on delay.(minimum 100msec)
> -
>  - USB Device:
>                 Define the below if you wish to use the USB console.
>                 Once firmware is rebuilt from a serial console issue the
> diff --git a/common/usb_hub.c b/common/usb_hub.c
> index 4875a51aceaf..2add4b97920f 100644
> --- a/common/usb_hub.c
> +++ b/common/usb_hub.c
> @@ -35,10 +35,6 @@
>  #include <asm/4xx_pci.h>
>  #endif
>
> -#ifndef CONFIG_USB_HUB_MIN_POWER_ON_DELAY
> -#define CONFIG_USB_HUB_MIN_POWER_ON_DELAY      1000
> -#endif
> -
>  #define USB_BUFSIZ     512
>
>  static struct usb_hub_device hub_dev[USB_MAX_HUB];
> @@ -142,7 +138,7 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
>          * Wait for power to become stable,
>          * plus spec-defined max time for device to connect
>          */
> -       mdelay(pgood_delay + CONFIG_USB_HUB_MIN_POWER_ON_DELAY);
> +       mdelay(pgood_delay + 1000);
>  }
>
>  void usb_hub_reset(void)
> diff --git a/include/configs/cm_t35.h b/include/configs/cm_t35.h
> index aae05e033303..f6acf6920524 100644
> --- a/include/configs/cm_t35.h
> +++ b/include/configs/cm_t35.h
> @@ -104,8 +104,6 @@
>  #define CONFIG_USB_DEVICE
>  #define CONFIG_USB_TTY
>  #define CONFIG_SYS_CONSOLE_IS_IN_ENV
> -/* This delay is really for slow-to-power-on USB sticks, not the hub */
> -#define CONFIG_USB_HUB_MIN_POWER_ON_DELAY 500
>
>  /* commands to include */
>  #include <config_cmd_default.h>
> diff --git a/include/configs/gw_ventana.h b/include/configs/gw_ventana.h
> index 33983907f228..188871630bd3 100644
> --- a/include/configs/gw_ventana.h
> +++ b/include/configs/gw_ventana.h
> @@ -188,7 +188,6 @@
>  #define CONFIG_USB_ETH_CDC
>  #define CONFIG_NETCONSOLE
>  #define CONFIG_SYS_USB_EVENT_POLL_VIA_CONTROL_EP
> -#define CONFIG_USB_HUB_MIN_POWER_ON_DELAY 1200
>
>  /* serial console (ttymxc1,115200) */
>  #define CONFIG_CONS_INDEX              1
> --
> 1.8.1.5
>

Stephen,

Sorry for the late reply - I'm just getting around to testing this
(and I realize that Marek already committed it which is ok by me).

I have a variety of USB Mass Storage devices that I tested when I was
looking at this and out of about 12 devices I found I had 1 'usb
stick' that requires 2100ms in order to respond and be successfully
scanned: 048d:1327 Integrated Technology Express, Inc 32GB USB stick.
I also found that rotational media (ie Seagate and Western Digital USB
drives) would not respond in 1000ms either which didn't surprise me as
I figured they needed some extra spin-up time. For all other devices I
had I found that 1000ms was adequate.

So do these devices I mention simply violate the USB spec?

I wonder if the delay should be able to be overridden with an env var
or an argument to 'usb start' to account for devices like this?

Regards,

Tim

On 06/03/2014 10:17 AM, Tim Harvey wrote:
> On Mon, May 19, 2014 at 1:21 PM, Stephen Warren <swarren@wwwdotorg.org> wrote:
>> From: Stephen Warren <swarren@nvidia.com>
>>
>> Now that we wait the correct specification-mandated time at the end of
>> usb_hub_power_on(), I suspect that CONFIG_USB_HUB_MIN_POWER_ON_DELAY has
>> no purpose.
>>
>> For cm_t35.h, we already wait longer than the original MIN_POWER_ON_DELAY,
>> so this change is safe.
>>
>> For gw_ventana.h, we will wait as long as the original MIN_POWER_ON_DELAY
>> iff pgood_delay was at least 200ms. I'm not sure if this is the case or
>> not, hence I've CC'd relevant people to test this change.

>> diff --git a/include/configs/gw_ventana.h b/include/configs/gw_ventana.h

>> -#define CONFIG_USB_HUB_MIN_POWER_ON_DELAY 1200

> Stephen,
> 
> Sorry for the late reply - I'm just getting around to testing this
> (and I realize that Marek already committed it which is ok by me).
> 
> I have a variety of USB Mass Storage devices that I tested when I was
> looking at this and out of about 12 devices I found I had 1 'usb
> stick' that requires 2100ms in order to respond and be successfully

Was that 2100ms or 1200ms? I ask because gw_ventana.h only had 1200, so
if devices require 2100ms then they presumably didn't work with the code
before my patch?

> scanned: 048d:1327 Integrated Technology Express, Inc 32GB USB stick.
> I also found that rotational media (ie Seagate and Western Digital USB
> drives) would not respond in 1000ms either which didn't surprise me as
> I figured they needed some extra spin-up time. For all other devices I
> had I found that 1000ms was adequate.
> 
> So do these devices I mention simply violate the USB spec?

I *think* so yes.

> I wonder if the delay should be able to be overridden with an env var
> or an argument to 'usb start' to account for devices like this?

Yes, perhaps it is worth U-Boot probing for longer than the minimum
time, either always or on-demand as requested by an environment
variable. The only downside would be that "usb start" would take longer
even in the absence of these broken(?) devices if we always delay
longer, rather than triggering the process via an environment variable.
Marek, what are your thoughts?

On Tuesday, June 03, 2014 at 06:38:30 PM, Stephen Warren wrote:

[...]

> Yes, perhaps it is worth U-Boot probing for longer than the minimum
> time, either always or on-demand as requested by an environment
> variable. The only downside would be that "usb start" would take longer
> even in the absence of these broken(?) devices if we always delay
> longer, rather than triggering the process via an environment variable.
> Marek, what are your thoughts?

I'd vouch for env variable, we do not want to inconvenience users because of 
such bugged devices.

Best regards,
Marek Vasut

On Tue, Jun 3, 2014 at 9:38 AM, Stephen Warren <swarren@wwwdotorg.org> wrote:
> On 06/03/2014 10:17 AM, Tim Harvey wrote:
>> On Mon, May 19, 2014 at 1:21 PM, Stephen Warren <swarren@wwwdotorg.org> wrote:
>>> From: Stephen Warren <swarren@nvidia.com>
>>>
>>> Now that we wait the correct specification-mandated time at the end of
>>> usb_hub_power_on(), I suspect that CONFIG_USB_HUB_MIN_POWER_ON_DELAY has
>>> no purpose.
>>>
>>> For cm_t35.h, we already wait longer than the original MIN_POWER_ON_DELAY,
>>> so this change is safe.
>>>
>>> For gw_ventana.h, we will wait as long as the original MIN_POWER_ON_DELAY
>>> iff pgood_delay was at least 200ms. I'm not sure if this is the case or
>>> not, hence I've CC'd relevant people to test this change.
>
>>> diff --git a/include/configs/gw_ventana.h b/include/configs/gw_ventana.h
>
>>> -#define CONFIG_USB_HUB_MIN_POWER_ON_DELAY 1200
>
>> Stephen,
>>
>> Sorry for the late reply - I'm just getting around to testing this
>> (and I realize that Marek already committed it which is ok by me).
>>
>> I have a variety of USB Mass Storage devices that I tested when I was
>> looking at this and out of about 12 devices I found I had 1 'usb
>> stick' that requires 2100ms in order to respond and be successfully
>
> Was that 2100ms or 1200ms? I ask because gw_ventana.h only had 1200, so
> if devices require 2100ms then they presumably didn't work with the code
> before my patch?

it was 2100ms for that particular device. I don't have in my notes why
I chose 1200 over 1000 but a quick test today showed all other USB
sticks I have worked fine with your 1000ms change.

>
>> scanned: 048d:1327 Integrated Technology Express, Inc 32GB USB stick.
>> I also found that rotational media (ie Seagate and Western Digital USB
>> drives) would not respond in 1000ms either which didn't surprise me as
>> I figured they needed some extra spin-up time. For all other devices I
>> had I found that 1000ms was adequate.
>>
>> So do these devices I mention simply violate the USB spec?
>
> I *think* so yes.
>
>> I wonder if the delay should be able to be overridden with an env var
>> or an argument to 'usb start' to account for devices like this?
>
> Yes, perhaps it is worth U-Boot probing for longer than the minimum
> time, either always or on-demand as requested by an environment
> variable. The only downside would be that "usb start" would take longer
> even in the absence of these broken(?) devices if we always delay
> longer, rather than triggering the process via an environment variable.
> Marek, what are your thoughts?

I wouldn't want to hard code a longer default and make everyone else
pay for abnormal devices.

Tim