On 8/13/12, Sean Cross <xobs@xxxxxxxx> wrote: > We're trying to get USB host mode working on a Freescale i.MX233. I'm > using > a chumby hacker board, but there are several people trying on an OlinuXino > board as well. We're running into a problem where every time the root hub > is detected, it's disconnected. This results in kernel messages such as: > > [ 66.410000] hub 1-0:1.0: unable to enumerate USB device on port 1 > [ 66.630000] hub 1-0:1.0: unable to enumerate USB device on port 1 > [ 66.850000] hub 1-0:1.0: unable to enumerate USB device on port 1 > [ 67.070000] hub 1-0:1.0: unable to enumerate USB device on port 1 > > It looks like we're running into this chip issue described in the i.MX233 > reference manual: > >> For host mode, enables high-speed disconnect detector. This signal >> allows the override of enabling the detection that is normally done in >> the UTMI controller. The UTMI controller enables this circuit whenever >> the host sends a start-of-frame packet. Due to a on chip issue (Errata >> #2791), software must pay attention to when to assert the >> ENHOSTDISCONDETECT bit in HW_USBPHY_CTRL register: >> 1. Only set HW_USBPHY_CTRL.ENHOSTDISCONDETECT during high speed >> host mode. >> 2. Do not set HW_USBPHY_CTRL.ENHOSTDISCONDETECT during the reset >> and speed negotiation period. >> 3. Do not set HW_USBPHY_CTRL.ENHOSTDISCONDETECT during host >> suspend/resume sequence. > > We suspect this because we can get it to detect a USB device when it first > boots by applying the following patch: > > diff --git a/drivers/usb/otg/mxs-phy.c b/drivers/usb/otg/mxs-phy.c > index c1a67cb..23eeae6 100644 > --- a/drivers/usb/otg/mxs-phy.c > +++ b/drivers/usb/otg/mxs-phy.c > @@ -81,8 +81,6 @@ static int mxs_phy_on_connect(struct usb_phy *phy, int > port) > dev_dbg(phy->dev, "Connect on port %d\n", port); > > mxs_phy_hw_init(to_mxs_phy(phy)); > - writel_relaxed(BM_USBPHY_CTRL_ENHOSTDISCONDETECT, > - phy->io_priv + HW_USBPHY_CTRL_SET); > > return 0; > } I applied this change and it allowed a mx23-olinuxino board to detect a USB pen drive. Peter, Is this change related to this hack in FSL kernel? http://opensource.freescale.com/git?p=imx/linux-2.6-imx.git;a=commitdiff;h=c44dc00d2aecfcbf30336180f5ecd6a3a633545d What would be the proper way to handle HOSTDISCONDETECT so that it can work for mx23 as well? Thanks, Fabio Estevam -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
