From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: Re: Diagnosing ACPI trouble related to pinctr_cherryview on 4.4.x
Date: Tue, 22 Mar 2016 17:22:18 +0200
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To: Martin Langhoff <martin.langhoff@gmail.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>, Linus Walleij <linus.walleij@linaro.org>, linux-gpio@vger.kernel.org, Andy Shevchenko <andriy.shevchenko@linux.intel.com>

On Tue, Mar 22, 2016 at 11:09:51AM -0400, Martin Langhoff wrote:
>    Hi pinctrl_cherryview maintainers.
>    I unsuspectingly bought a laptop for a family member which hits trouble
>    with pinctrl_cherryview; it only boots with the module blacklisted or
>    acpi=off .
>    System is (trying) to run Fedora 23 -- made more difficult by recent
>    Fedora kernels having the module built-in.
>    Are there any useful debugging steps I can follow to narrow this down?
>    Already tried the acpi diagnostics steps (acpi=ht, etc) to no avail.
>    thank you!

I think this is a known issue.

Please disable dw_dmac from your .config (or blacklist the module):

  CONFIG_DW_DMAC_CORE=n
  CONFIG_DW_DMAC=n

You can also enable pinctrl-cherryview.c.

Andy (Cc'd) is working a fix for this DMA hang issue.