From: Lukas Wunner <lukas@wunner.de>
To: Minas Harutyunyan <minas.harutyunyan@synopsys.com>
Cc: Stefan Wahren <stefan.wahren@i2se.com>,
Jisheng Zhang <Jisheng.Zhang@synaptics.com>,
Woojung Huh <woojung.huh@microchip.com>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-rpi-kernel@lists.infradead.org"
<linux-rpi-kernel@lists.infradead.org>,
Douglas Anderson <dianders@chromium.org>
Subject: Re: lan78xx: About 8000 usb interrupts per second when idle
Date: Sun, 14 Apr 2019 21:46:23 +0200 [thread overview]
Message-ID: <20190414194623.afp3fanjuq72ctln@wunner.de> (raw)
In-Reply-To: <BN6PR1201MB008219D0CF1CB7CF7F802008A72D0@BN6PR1201MB0082.namprd12.prod.outlook.com>
On Tue, Apr 09, 2019 at 09:28:16AM +0000, Minas Harutyunyan wrote:
> Am 09.04.19 um 08:54 schrieb Jisheng Zhang:
> > The second one: 8000 usb interrupts per second when idle.
> > This is abnormal. any idea? Is it due to the lan78xx?
>
> dwc2 in host mode enable SOF interrupts if any periodic EP are in use.
> So, 8000 interrupts per second is expectant behavior.
The dwc_otg driver patched into the Raspberry Pi Foundation's
kernel seems to make do with much fewer interrupts and much
lower CPU load. How does it do that and how could dwc2 be
made to do the same? Would it be possible for you to provide
me with documentation on the chip? The Synopsis website
requires registration for downloads and registration requires
a Synopsis customer ID.
It seems the Foundation's dwc_otg driver was forked from code
that later begat dwc2.
Thanks,
Lukas
next prev parent reply other threads:[~2019-04-14 19:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190408143443.335f7e93@xhacker.debian>
[not found] ` <002929b7-9a0d-6d92-4e03-18a6748c6708@i2se.com>
[not found] ` <20190408160551.03911b27@xhacker.debian>
[not found] ` <20190409144655.753d3bd9@xhacker.debian>
2019-04-09 7:18 ` lan78xx: About 8000 usb interrupts per second when idle Stefan Wahren
2019-04-09 9:28 ` Minas Harutyunyan
2019-04-10 9:37 ` Jisheng Zhang
2019-04-10 10:08 ` Oliver Neukum
2019-04-14 19:46 ` Lukas Wunner [this message]
2019-04-15 0:53 ` Woojung.Huh
2019-04-15 17:35 ` Doug Anderson
2019-04-15 18:15 ` Alan Stern
2019-04-14 21:51 Paul Zimmerman
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