From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Date: Mon, 19 Dec 2011 13:07:39 +0100 Subject: [U-Boot] [PATCH] ehci: speed up initialization In-Reply-To: References: <1323125542-6286-1-git-send-email-vpalatin@chromium.org> Message-ID: <4EEF290B.9060106@grandegger.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 12/10/2011 05:29 PM, Remy Bohmer wrote: > Hi, > > 2011/12/5 Vincent Palatin : >> According to EHCI specification v1.0, the controller should stabilize >> the power on a port at most 20 ms after the port power bit transition. >> So, we put this setting in the virtual descriptor corresponding field, >> (bPwrOn2PwrGood = 10 => 10 x 2ms = 20ms), this saves about 500ms at each >> controller initialization/enumeration. >> >> Signed-off-by: Vincent Palatin >> --- >> drivers/usb/host/ehci-hcd.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) > > Applied to u-boot-usb. I just realized that this patch breaks "usb start" on my mx53loco board: MX53LOCO U-Boot > usb start (Re)start USB... USB: Register 10011 NbrPorts 1 USB EHCI 1.00 scanning bus for devices... 1 USB Device(s) found scanning bus for storage devices... 0 Storage Device(s) found scanning bus for ethernet devices... 0 Ethernet Device(s) found MX53LOCO U-Boot > usb start (Re)start USB... USB: Register 10011 NbrPorts 1 USB EHCI 1.00 scanning bus for devices... 2 USB Device(s) found scanning bus for storage devices... 0 Storage Device(s) found scanning bus for ethernet devices... 1 Ethernet Device(s) found The device is not found at the first attempt. Obviously, a value of 10 for bPwrOn2PwrGood seems too short but 20 works fine. Would that be a resonable compromise? If yes, I could send a patch. Wolfgang. Wolfgang.