Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 7 May 2020 16:03:15 -0500
From:   Rob Herring <robh@kernel.org>
To:     Marc Zyngier <maz@kernel.org>
Cc:     linux-pci@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Bjorn Helgaas <bhelgaas@google.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Yue Wang <yue.wang@Amlogic.com>
Subject: Re: [PATCH] PCI: amlogic: meson: Don't use FAST_LINK_MODE to set up
 link
Message-ID: <20200507210315.GA19547@bogus>
References: <20200429164230.309922-1-maz@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200429164230.309922-1-maz@kernel.org>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, 29 Apr 2020 17:42:30 +0100, Marc Zyngier wrote:
> My vim3l board stubbornly refuses to play ball with a bog
> standard PCIe switch (ASM1184e), spitting all kind of errors
> ranging from link never coming up to crazy things like downstream
> ports falling off the face of the planet.
> 
> Upon investigating how the PCIe RC is configured, I found the
> following nugget: the Sysnopsys DWC PCIe Reference Manual, in the
> section dedicated to the PLCR register, describes bit 7 (FAST_LINK_MODE)
> as:
> 
> "Sets all internal timers to fast mode for simulation purposes."
> 
> I completely understand the need for setting this bit from a simulation
> perspective, but what I have on my desk is actual silicon, which
> expects timers to have a nominal value (and I expect this is the
> case for most people).
> 
> Making sure the FAST_LINK_MODE bit is cleared when configuring the RC
> solves this problem.
> 
> Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  drivers/pci/controller/dwc/pci-meson.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Acked-by: Rob Herring <robh@kernel.org>