From: Neil Armstrong <narmstrong@baylibre.com>
To: thilo <thibau@gmx.de>
Cc: linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org
Subject: Re: Delay recognizing USB-Drive with Kernel 5.9.12
Date: Mon, 18 Jan 2021 14:37:03 +0100 [thread overview]
Message-ID: <7655b38c-a1dc-7207-4fa3-e1321e414a74@baylibre.com> (raw)
In-Reply-To: <3b5d2496-9be6-fdef-5e12-27def85aeb5b@gmx.de>
Hi,
On 15/01/2021 15:27, thilo wrote:
> Hello!
> I am new to linux, please excuse false statements :-)).
> I think there is a USB_PWR_EN-problem in the kernel (UAS-driver???)
> NO delay recognizing USB-drive with kernel 4.9.247
>>20 sec delay recognizing USB-drive with kernel 5.9.12
>
> Installed Armbian on SD on an Odroid n2+.
> Wanted to move system to USB-SSD, used nand-sata-install.
> After that, didn't boot.
> New install on SD.
> Realized that most of the time it took >20 sec to recognize USB-SSD.
> I felt, failing boot was due to slow USB-drive recognition (system drive
> not available at boot).
>
> in kern.log:
> ... localhost kernel: [ 33.760038] USB_PWR_EN: disabling
> ...
> ... localhost kernel: [ 587.836268] usb 1-1.3: new full-speed USB
> device number 6 using xhci-hcd
>
> Did some research, found:
> https://forum.armbian.com/topic/13580-odroid-n2-kernel49-no-boot-on-usb-sata-ssd/
> with:
> 'BTW what is USB_PWR_EN, are we looking at something interesting here?'
USB_PWR_EN is the regulator that powers the micro USB OTG port, when nothing
is connected or a is connected to a PC, power is disabled.
Connecting a device via a microUSB-to-USB-A cable will enable this regulator.
> and a link to:
> https://forum.armbian.com/topic/11741-boot-from-ssd-with-n2/page/3/
> with:
> 'None ... delay was necessary when using kernel 4.9.x so ... seems ...
> problem with the 5.x kernel series, presumably around the UAS driver ...'
>
> With Armbian-config, changed
> Kernel 5.9.12 to 4.9.247 (gladly very easy with that!)
> After that recognition of USB-SSD was fast.
> Another nand-sata-install.
> New boot, worked: root part is on USB-SSD!!!
>
> So: problem with 5.x kernel, see top of mail.
>
> Would be glad to get feedback.
As Martin says, the Amlogic kernel contains a lot a tweaks which are not present
on the mainlinx Linue tree, maybe if you identify what delays this detection we may
find how to reduce such delays on Amlogic SoCs.
Neil
>
> Thilo
>
>
> _______________________________________________
> linux-amlogic mailing list
> linux-amlogic@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-amlogic
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
prev parent reply other threads:[~2021-01-18 13:37 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-15 14:27 Delay recognizing USB-Drive with Kernel 5.9.12 thilo
2021-01-16 19:56 ` Martin Blumenstingl
2021-01-18 13:37 ` Neil Armstrong [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7655b38c-a1dc-7207-4fa3-e1321e414a74@baylibre.com \
--to=narmstrong@baylibre.com \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=thibau@gmx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).