From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Date: Sun, 02 Aug 2015 17:25:12 +0100 Subject: [U-Boot] [PATCH 1/3] sunxi: usb-phy: Never power off the usb ports In-Reply-To: <1438433451-17720-1-git-send-email-hdegoede@redhat.com> References: <1438433451-17720-1-git-send-email-hdegoede@redhat.com> Message-ID: <1438532712.18644.15.camel@hellion.org.uk> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Sat, 2015-08-01 at 14:50 +0200, Hans de Goede wrote: > USB devices are not really designed to get the power bounced off and on > at them. Esp. USB powered harddisks do not like this. > > Currently we power off the USB ports both on a "usb reset" and when > booting the kernel, causing the usb-power to bounce off and then back > on again. > > This patch removes the powering off calls, fixing the undesirable power > bouncing. > > Note this requires some special handling for the OTG port: > 1) We must skip the external vbus check if we've already enabled our own > vbus to avoid false positives > 2) If on an usb reset we no longer detect that the id-pin is grounded, turn > off vbus as that means an external vbus may be present now > > Signed-off-by: Hans de Goede Acked-by: Ian Campbell