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Date:   Mon, 28 Jun 2021 08:53:02 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Jung Daehwan <dh10.jung@samsung.com>
Cc:     Mathias Nyman <mathias.nyman@intel.com>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: usb: host: Reduce xhci_handshake timeout in xhci_reset
Message-ID: <YNlxzj7KXG43Uyrp@kroah.com>
References: <CGME20210622113915epcas2p284c61291fc9d83487f6dfebb65fd4e9b@epcas2p2.samsung.com>
 <1624361096-41282-1-git-send-email-dh10.jung@samsung.com>
 <YNJAZDwuFmEoTJHe@kroah.com>
 <20210628022548.GA69289@ubuntu>
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On Mon, Jun 28, 2021 at 11:25:48AM +0900, Jung Daehwan wrote:
> On Tue, Jun 22, 2021 at 09:56:20PM +0200, Greg Kroah-Hartman wrote:
> > On Tue, Jun 22, 2021 at 08:24:56PM +0900, Daehwan Jung wrote:
> > > It seems 10 secs timeout is too long in general case. A core would wait for
> > > 10 secs without doing other task and it can be happended on every device.
> > 
> > Only if the handshake does not come back sooner, right?
> 
> Yes, right.
> 
> > What is causing your device to timeout here?
> 
> Host Controller doesn't respond handshake. I don't know why and I ask HW team
> to debug it.

Please work to fix your hardware, that feels like the root of the
problem here.  If you require the timeout for xhci_reset() to happen,
then how do you know that the hardware really did reset properly in the
reduced amount of time you just provided?

thanks,

greg k-h