Re: [PATCH] i.MX6 PCIe: Fix imx6_pcie_deassert_core_reset() polarity

From: Fabio Estevam
Date: Mon Mar 28 2016 - 18:13:25 EST


On Mon, Mar 28, 2016 at 7:06 PM, Tim Harvey <tharvey@xxxxxxxxxxxxx> wrote:

>> On imx6qdl-sabresd.dtsi the PCI reset gpio polarity is set to high,
>> which is not correct, so the Wifi card could be detected even with
>> 5c5fb40de8f. So two errors in sequence and PCI still works on this
>> board :-)
>
> ouch - two wrongs did make a right!
>
> It's not too easy to tell how many IMX6 boards incorrectly specify
> their reset-gpio polarity. I don't know what the best way to determine
> what boards use the IMX6 pcie host controller. Is there a dtc usage
> that will display the compiled dtb's then we grep out 'compatible =
> "fsl,imx6q-pcie"' to at least get the list of boards to inspect? I'm
> curious if its just one or two boards that incorrectly specify the
> polarity of their PCI reset.

In order to keep old dtb's working we should simply ignore the GPIO
flags passed in the 'reset-gpio' property.

That's why we need a revert. Just sent a v2, BTW.