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From: Heiko Stuebner <heiko@sntech.de>
To: Douglas Anderson <dianders@chromium.org>
Cc: John Youn <John.Youn@synopsys.com>,
	balbi@ti.com, Yunzhi Li <lyz@rock-chips.com>,
	linux-rockchip@lists.infradead.org,
	Julius Werner <jwerner@chromium.org>,
	gregory.herrero@intel.com, yousaf.kaukab@intel.com,
	dinguyen@opensource.altera.com, johnyoun@synopsys.com,
	gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] dwc2: Speed up the interrupt handler quite a bit
Date: Thu, 05 Nov 2015 20:18:56 +0100	[thread overview]
Message-ID: <4257088.ij6Pk572Sd@phil> (raw)
In-Reply-To: <1446677585-28582-1-git-send-email-dianders@chromium.org>

Am Mittwoch, 4. November 2015, 14:53:02 schrieb Douglas Anderson:
> The dwc2 interrupt handler is quite slow.  On rk3288 with a few things
> plugged into the ports and with cpufreq locked at 696MHz (to simulate
> real world idle system), I can easily observe dwc2_handle_hcd_intr()
> taking > 120 us, sometimes > 150 us.  Note that SOF interrupts come
> every 125 us with high speed USB, so taking > 120 us in the interrupt
> handler is a big deal.
> 
> The patches here will speed up the interrupt controller significantly.
> After this series, I have a hard time seeing the interrupt controller
> taking > 20 us and I don't ever see it taking > 30 us ever in my tests
> unless I bring the cpufreq back down.  With the cpufreq at 126 MHz I can
> still see the interrupt handler take > 50 us, so I'm sure we could
> improve this further.  ...but hey, it's a start.
> 
> In addition to the speedup, this series also has the advantage of
> simplifying dwc2 and making it more like everyone else (introducing the
> possibility of future simplifications).  Picking this series up will
> help your diffstat and likely win you friends.  ;)

I gave this a simple spin on my veyron-pinky with both a device attached 
directly to the port as well as with an usb-hub in between. Everything was 
still working smoothly, so

Tested-by: Heiko Stuebner <heiko@sntech.de>

WARNING: multiple messages have this Message-ID (diff)
From: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
To: Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Cc: gregory.herrero-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org,
	johnyoun-HKixBCOQz3hWk0Htik3J/w@public.gmane.org,
	gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org,
	linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	balbi-l0cyMroinI0@public.gmane.org,
	John Youn <John.Youn-HKixBCOQz3hWk0Htik3J/w@public.gmane.org>,
	linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	yousaf.kaukab-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org,
	Yunzhi Li <lyz-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	Julius Werner <jwerner-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
	dinguyen-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org
Subject: Re: [PATCH 0/3] dwc2: Speed up the interrupt handler quite a bit
Date: Thu, 05 Nov 2015 20:18:56 +0100	[thread overview]
Message-ID: <4257088.ij6Pk572Sd@phil> (raw)
In-Reply-To: <1446677585-28582-1-git-send-email-dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>

Am Mittwoch, 4. November 2015, 14:53:02 schrieb Douglas Anderson:
> The dwc2 interrupt handler is quite slow.  On rk3288 with a few things
> plugged into the ports and with cpufreq locked at 696MHz (to simulate
> real world idle system), I can easily observe dwc2_handle_hcd_intr()
> taking > 120 us, sometimes > 150 us.  Note that SOF interrupts come
> every 125 us with high speed USB, so taking > 120 us in the interrupt
> handler is a big deal.
> 
> The patches here will speed up the interrupt controller significantly.
> After this series, I have a hard time seeing the interrupt controller
> taking > 20 us and I don't ever see it taking > 30 us ever in my tests
> unless I bring the cpufreq back down.  With the cpufreq at 126 MHz I can
> still see the interrupt handler take > 50 us, so I'm sure we could
> improve this further.  ...but hey, it's a start.
> 
> In addition to the speedup, this series also has the advantage of
> simplifying dwc2 and making it more like everyone else (introducing the
> possibility of future simplifications).  Picking this series up will
> help your diffstat and likely win you friends.  ;)

I gave this a simple spin on my veyron-pinky with both a device attached 
directly to the port as well as with an usb-hub in between. Everything was 
still working smoothly, so

Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>

  parent reply	other threads:[~2015-11-05 19:19 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-04 22:53 [PATCH 0/3] dwc2: Speed up the interrupt handler quite a bit Douglas Anderson
2015-11-04 22:53 ` Douglas Anderson
2015-11-04 22:53 ` [PATCH 1/3] usb: dwc2: rockchip: Make the max_transfer_size automatic Douglas Anderson
2015-11-04 22:53 ` [PATCH 2/3] usb: dwc2: host: Giveback URB in tasklet context Douglas Anderson
2015-11-04 22:53   ` Douglas Anderson
2015-11-05  0:30   ` Doug Anderson
2015-11-05  0:30     ` Doug Anderson
2015-11-05 15:19     ` Alan Stern
2015-11-06  0:29       ` Doug Anderson
2015-11-06 15:40         ` Alan Stern
2015-11-07  1:26           ` Doug Anderson
2015-11-07 15:09             ` Alan Stern
2015-11-04 22:53 ` [PATCH 3/3] usb: dwc2: host: Get aligned DMA in a more supported way Douglas Anderson
2015-11-05 19:18 ` Heiko Stuebner [this message]
2015-11-05 19:18   ` [PATCH 0/3] dwc2: Speed up the interrupt handler quite a bit Heiko Stuebner

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