From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Thu, 10 Mar 2016 17:06:35 -0700 Subject: [U-Boot] [PATCH 2/6] usb: Remove 200 ms delay in usb_hub_port_connect_change() In-Reply-To: <1457625012-1268-3-git-send-email-sr@denx.de> References: <1457625012-1268-1-git-send-email-sr@denx.de> <1457625012-1268-3-git-send-email-sr@denx.de> Message-ID: <56E20C0B.9090901@wwwdotorg.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 03/10/2016 08:50 AM, Stefan Roese wrote: > This patch removes 2 mdelay(200) calls from usb_hub_port_connect_change(). > These delays don't seem to be necessary. At least not in my tests. Here > the number for a custom x86 Bay Trail board (not in mainline yet) with > a quite large and complex USB hub infrastructure. > > Without this patch: > starting USB... > USB0: USB EHCI 1.00 > scanning bus 0 for devices... 9 USB Device(s) found > > time: 28.415 seconds > > With this patch: > starting USB... > USB0: USB EHCI 1.00 > scanning bus 0 for devices... 9 USB Device(s) found > > time: 24.811 seconds > > So ~3.5 seconds of USB scanning time reduction. > > These mdelay calls are removed if CONFIG_USB_FAST_SCAN is defined. They > are not removed per default yet. It would be good to test with this > option enabled on many other boards. And once we have a good testing > base we can decide to remove these delays completely, including this > macro. This patch, Tested-by: Stephen Warren