Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 06 Feb 2018 21:44:52 +0000
From:      bugzilla-noreply@freebsd.org
To:        freebsd-arm@FreeBSD.org
Subject:   [Bug 225713] Zynq/Zedboard GPIO driver can reset USB port on some boards
Message-ID:  <bug-225713-7@https.bugs.freebsd.org/bugzilla/>

next in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D225713

            Bug ID: 225713
           Summary: Zynq/Zedboard GPIO driver can reset USB port on some
                    boards
           Product: Base System
           Version: CURRENT
          Hardware: arm
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: arm
          Assignee: freebsd-arm@FreeBSD.org
          Reporter: thoma555-bsd@yahoo.com

Created attachment 190368
  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D190368&action=
=3Dedit
patch for sys/arm/xilinx/zy7_gpio.c

The Zynq/Zedboard GPIO driver attempts to tri-state all GPIO pins on boot up
but the order in which I reset the hardware can cause the pins to be briefly
held low before being tri-stated.  This is a problem on boards that use GPIO
pins to reset devices.

In particular, the Zybo and ZC-706 boards use a GPIO pin as a USB PHY reset=
.=20
If U-boot enables the USB port before booting the kernel, the GPIO driver
attach causes a glitch on the USB PHY reset and the USB port loses power.  =
My
fix is to have the GPIO driver leave the pins in whatever configuration U-b=
oot
placed them.

--=20
You are receiving this mail because:
You are the assignee for the bug.=



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-225713-7>