On Wed, 3 Dec 2014, walkrain wrote: > Hi Stern: > Good afternoon ! Messages like this should always be CC'ed to the linux-usb@xxxxxxxxxxxxxxx mailing list. > I am a software engineer in Spreadtrum company in Shanghai,China. > Recently I met a usb issue: > when I plug my mass_storage u-disk to my smart-phone platform and play music from the u-disk > sometimes it will occurs some errors as follow: > 01-01 01:22:21.259 <3>[ 4950.969390] c1 hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling... > I have found that you have a commit on kernel on Fri,Aug 24 2007: > > commit 14c04c0f88f228fee1f412be91d6edcb935c78aa > Author: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > Date: Fri Aug 24 15:40:19 2007 -0400 > USB: reorganize urb->status use in ehci-hcd > This patch (as974) reorganizes the way ehci-hcd sets urb->status. It > now keeps the information in a local variable until the last moment. > The patch also simplifies the handling of -EREMOTEIO, since the only > use of that code is to set the do_status flag. > Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > CC: David Brownell <david-b@xxxxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx> > diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c > index a8f5408..794d27e 100644 > --- a/drivers/usb/host/ehci-q.c > +++ b/drivers/usb/host/ehci-q.c > > but my SOC USB IP is DWC_otg (synopsys product) > and I am not very familiar with dwc_otg driver very well > do you know: > what usb transfer error that will make usb controller root hub disable? I don't know anything about the DWC controller. That's why it's important to use the mailing list -- so that your message will be seen by the people who are able to help. In general, a hub will disable a port if the device attached to that port babbles (sends data at the wrong time). Electromagnetic interference or a bad connection can have the same effect. Alan Stern -- 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
