From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Thu, 28 Mar 2013 15:28:03 +0100 Subject: [U-Boot] [PATCH 2/7] usb: hub: Conditionally power on usb's root-hub ports In-Reply-To: <1364376543-7526-3-git-send-email-gautam.vivek@samsung.com> References: <1364376543-7526-1-git-send-email-gautam.vivek@samsung.com> <1364376543-7526-3-git-send-email-gautam.vivek@samsung.com> Message-ID: <201303281528.03266.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Vivek Gautam, > Power on root hubs' ports only when they are not yet powered on. > Its seen with USB 3.0 ports that they are powered on after > a H/W reset, as also reflected in XHCI spec (sec 4.3): > "After a Chip Hardware Reset, HCRST, or commanded to the > PLS = RxDetect state, all Root Hub ports shall be in Disconnected > state, i.e. the port is powered on (PP = 1)" > > Signed-off-by: Amar > Signed-off-by: Vivek Gautam Just wondering if we shouldn't power-cycle all the ports instead -- aka. turn them off and then turn all of them on again. Best regards, Marek Vasut