From: Stephen Warren <swarren@wwwdotorg.org>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v2 0/4] usb: Reduce USB scanning time
Date: Fri, 11 Mar 2016 10:53:02 -0700 [thread overview]
Message-ID: <56E305FE.8030009@wwwdotorg.org> (raw)
In-Reply-To: <1457708151-24287-1-git-send-email-sr@denx.de>
On 03/11/2016 07:55 AM, Stefan Roese wrote:
>
> My current x86 platform (Bay Trail, not in mainline yet) has a quite
> complex USB infrastructure with many USB hubs. Here the USB scan takes
> an incredible huge amount of time:
>
> starting USB...
> USB0: USB EHCI 1.00
> scanning bus 0 for devices... 9 USB Device(s) found
>
> time: 28.415 seconds
>
> This is of course not acceptable on platforms, where USB needs to get
> scanned at every bootup. As this increases the bootup time of this
> device by nearly 30 seconds!
>
> This patch series greatly reduces the USB scanning time. This is done
> by multiple means:
>
> - Remove or reduce delays and timeouts
> - Remove a 2nd reset of the USB hubs
> - Change USB port timeout handling and introduce quasi parallel USB
> port scanning
>
> As a result, the USB scanning time is greatly reduced:
>
> starting USB...
> USB0: USB EHCI 1.00
> scanning bus 0 for devices... 9 USB Device(s) found
>
> time: 4.606 seconds
>
> As you can see, the time is reduced from 28.4 to 4.6 seconds!
>
> Please find more details to the changes in the patch description.
>
> Testing and comments welcome!
The series,
Tested-by: Stephen Warren <swarren@nvidia.com>
(same set of tests as last time)
next prev parent reply other threads:[~2016-03-11 17:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-11 14:55 [U-Boot] [PATCH v2 0/4] usb: Reduce USB scanning time Stefan Roese
2016-03-11 14:55 ` [U-Boot] [PATCH v2 1/4] usb: legacy_hub_port_reset(): Speedup hub reset handling Stefan Roese
2016-03-11 14:55 ` [U-Boot] [PATCH v2 2/4] usb: Remove 200 ms delay in usb_hub_port_connect_change() Stefan Roese
2016-03-11 14:55 ` [U-Boot] [PATCH v2 3/4] usb: Don't reset the USB hub a 2nd time Stefan Roese
2016-03-11 14:55 ` [U-Boot] [PATCH v2 4/4] usb: Change power-on / scanning timeout handling Stefan Roese
2016-03-11 17:53 ` Stephen Warren [this message]
2016-03-11 19:01 ` [U-Boot] [PATCH v2 0/4] usb: Reduce USB scanning time Hans de Goede
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