From: John Keeping <john@metanate.com>
To: Minas Harutyunyan <minas.harutyunyan@synopsys.com>
Cc: Felipe Balbi <balbi@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb@vger.kernel.org, John Youn <john.youn@synopsys.com>
Subject: usb: dwc2: gadget: Consider VBUS discharge time in disconnect flow
Date: Wed, 6 Feb 2019 18:52:43 +0000 [thread overview]
Message-ID: <20190206185243.3b35220d@donbot> (raw)
On Tue, 5 Feb 2019 12:08:48 +0400
Minas Harutyunyan <minas.harutyunyan@synopsys.com> wrote:
> If VBUS discharge time > 3ms then on device cable disconnect, core
> asserted Early Suspend then Suspend interrupts which no need to
> handle.
>
> VBUS discharge time depend on PHY schematic implementation.
> Can be up to 1 sec.
>
> To unambiguous recognize disconnect event on Early_Suspend interrupt
> added delay to allow VBUS fully discharge and as result
> GOTGCTL_BSESVLD goes to 0. If GOTGCTL_BSESVLD after delay still set
> to 1 that mean Suspend initiated by host, not by disconnect.
> In case of disconnect after Early_Suspend core asserting Suspend,
> Reset Detect and Reset interrupts which no any meaning, so these
> interrupts no need to handle and resetting in GINTSTS.
I have just tried this and it makes enumeration much slower. The host
system shows:
[1495332.243080] usb 1-2.4.7: new high-speed USB device number 89 using xhci_hcd
[1495337.399713] usb 1-2.4.7: device descriptor read/64, error -110
[1495347.779878] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[1495348.004513] usb 1-2.4.7: New USB device found, idVendor=0001, idProduct=0001, bcdDevice= 1.01
My guess is that the added delay is triggering in cases when it
shouldn't and delaying the response to the setup device command.
next reply other threads:[~2019-02-06 18:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-06 18:52 John Keeping [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-02-07 11:15 usb: dwc2: gadget: Consider VBUS discharge time in disconnect flow Felipe Balbi
2019-02-05 8:08 Minas Harutyunyan
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