Subject: Re: [PATCH 2/2] PCI: armada8k: don't toggle reset twice

From: Andrew Lunn <[email-masked]>
Date: Thu, 10 Jan 2019 13:55:48 +0100

On Thu, Jan 10, 2019 at 02:26:22PM +0200, Baruch Siach wrote:
> Commit 3d71746c42 ("PCI: armada8k: Add support for gpio controlled reset
> signal") added reset signal support. Reset is unconditionally asserted
> and deasserted.
> 
> Unfortunately, that commit breaks boot on Macchiatobin when a Mellanox
> NIC is in the PCIe slot.
> 
> It turns out that you can toggle the reset signal only once. Another
> reset signal toggle makes access to PCI configuration registers stall
> indefinitely. U-Boot toggles the Macchiatobin PCIe reset line already at
> boot.

Hi Baruch

Is this double reset issue limited to just Mellanox NICs, or any
device in the PCIe slot?

This sounds more like a workaround than a fix. It would be good to
investigate further and determine which end of the PCIe link has the
problem.

Thanks
	Andrew

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