From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Mon, 16 Jan 2017 12:14:03 +0100 Subject: USB: OHCI: high softirq load In-Reply-To: References: <20170116100220.0b00658e@bbrezillon> Message-ID: <20170116121403.4a3a7b17@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, 16 Jan 2017 11:54:23 +0100 Antoine Aubert wrote: > Also, I made a big misunderstanding > > With EHCI + OHCI = high level of softirq (USB2.0) Well, the number of irqs and softirqs are likely to be related (you usually trigger a softirq after you received an hardirq). > > OHCI only = normal level What about EHCI only? And what happens if you only plug 1 device? Please share the content of /proc/interrupts (and everything you think is relevant) for each of these cases. > > Le 16/01/2017 ? 11:31, Antoine Aubert a ?crit : > > Thx for your answer Boris > > > > Le 16/01/2017 ? 10:02, Boris Brezillon a ?crit : > >> Hi Antoine, > >> > >> On Mon, 16 Jan 2017 08:45:58 +0100 > >> Antoine Aubert wrote: > >> > >>> Hi, > >>> > >>> Im working on a AT91SAM9G25cu board > >>> (arch/arm/boot/dts/at91-kizboxmini.dts). We use linux-4.1.31, and when > >>> OHCI is enabled, I got some wired effects. > >> Can you test on a more recent kernel (4.9 or 4.10-rc4)? > > I'll give a try, just need little time ;) > >>> eg with 3 FTDI pluged, interrupts: more than 3.5k/s, cpu softirq > 24%, > >>> loadavg > 0.5 > >> Can you check which interrupt is triggered (cat /proc/interrupts), > > cat /proc/interrupts > > CPU0 > > 16: 2286 atmel-aic 1 Level pmc, at91_tick, at91_rtc, ttyS0 > > 17: 0 PMC 17 Level main_rc_osc > > 18: 0 PMC 0 Level main_osc > > 19: 0 PMC 16 Level mainck > > 20: 0 PMC 1 Level clk-plla > > 21: 0 PMC 6 Level clk-utmi > > 22: 0 PMC 3 Level clk-master > > 23: 945527 atmel-aic 17 Level tc_clkevt > > 24: 21815 atmel-aic 20 Level at_hdmac > > 25: 0 atmel-aic 21 Level at_hdmac > > 30: 120299 atmel-aic 24 Level eth0 > > 31: 22783651 atmel-aic 22 Level ehci_hcd:usb1, ohci_hcd:usb2 > > 99: 0 GPIO 16 Edge PB_RST > > 100: 0 GPIO 17 Edge PB_PROG > > Err: 0 > > > >> and > >> enable debug messages in drivers/usb/host/ohci-at91.c? Actually, I was asking for debug messages. You can enable them dynamically with dynamic printk [1]. BTW, please use pastebin (or any other alternative) to share these information. Thanks, Boris [1]http://lxr.free-electrons.com/source/Documentation/dynamic-debug-howto.txt