linux-kernel - Re: [PATCH] arm64: dts: rockchip: align bindings to PCIe spec

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Message-ID: <e8524bf8-a90c-423f-8a58-9ef05a3db1dd@rock-chips.com>
Date: Fri, 14 Nov 2025 17:16:21 +0800
From: Shawn Lin <shawn.lin@...k-chips.com>
To: Geraldo Nascimento <geraldogabriel@...il.com>
Cc: shawn.lin@...k-chips.com, Lorenzo Pieralisi <lpieralisi@...nel.org>,
 Krzysztof Wilczyński <kwilczynski@...nel.org>,
 Manivannan Sadhasivam <mani@...nel.org>, Rob Herring <robh@...nel.org>,
 Bjorn Helgaas <bhelgaas@...gle.com>, Heiko Stuebner <heiko@...ech.de>,
 linux-pci <linux-pci@...r.kernel.org>,
 linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
 linux-kernel <linux-kernel@...r.kernel.org>,
 devicetree <devicetree@...r.kernel.org>, krzk+dt <krzk+dt@...nel.org>,
 conor+dt <conor+dt@...nel.org>, Johan Jonker <jbx6244@...il.com>,
 linux-rockchip <linux-rockchip@...ts.infradead.org>,
 Simon Glass <sjg@...omium.org>, Philipp Tomsich <philipp.tomsich@...ll.eu>,
 Kever Yang <kever.yang@...k-chips.com>, Tom Rini <trini@...sulko.com>,
 u-boot@...ts.denx.de, 张烨 <ye.zhang@...k-chips.com>
Subject: Re: [PATCH] arm64: dts: rockchip: align bindings to PCIe spec

在 2025/11/14 星期五 12:41, Geraldo Nascimento 写道:
> On Wed, Nov 12, 2025 at 10:09:15PM -0300, Geraldo Nascimento wrote:
>> Hi Ye, Shawn,
>>
>> Here's more contained workaround without resorting to clearing DDR to
>> INPUT for every GPIO:
>>
>> diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
>> index ee1822ca01db..1d89131ec6ac 100644
>> --- a/drivers/pci/controller/pcie-rockchip-host.c
>> +++ b/drivers/pci/controller/pcie-rockchip-host.c
>> @@ -315,7 +315,8 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip)
>>   			    PCIE_CLIENT_CONFIG);
>>   
>>   	msleep(PCIE_T_PVPERL_MS);
>> -	gpiod_set_value_cansleep(rockchip->perst_gpio, 1);
>> +	gpiod_direction_input(rockchip->perst_gpio);
>> +	gpiod_direction_output(rockchip->perst_gpio, 1);
>>   
>>   	msleep(PCIE_RESET_CONFIG_WAIT_MS);
>>   
>> This results in working PCIe for me, pass initial link training.
> 
> Sorry for the inconvenience of more mail, but I'm providing as much
> detail as I can.
> 

Don't worry, it's helpful, so I think Ye could have a look.
May I ask if the failure only happened to one specific board?

Another thing I noticed is about one commit:
114b06ee108c ("PCI: rockchip: Set Target Link Speed to 5.0 GT/s before 
retraining")

It said: "Rockchip controllers can support up to 5.0 GT/s link speed."
But we issued an errata long time ago to announced it doesn't, you could
also check the PCIe part of RK3399 datasheet:
https://opensource.rock-chips.com/images/d/d7/Rockchip_RK3399_Datasheet_V2.1-20200323.pdf

Also we set max-link-speed to ONE in rk3399-base.dtsi but seems another
patch slip in: 755fff528b1b ("arm64: dts: rockchip: add variables for 
pcie completion to helios64")

> This hack has been confirmed to work in U-boot also.
> 
> diff --git a/drivers/pci/pcie_rockchip.c b/drivers/pci/pcie_rockchip.c
> index 19f9e58a640..5702b607ee6 100644
> --- a/drivers/pci/pcie_rockchip.c
> +++ b/drivers/pci/pcie_rockchip.c
> @@ -329,8 +329,10 @@ static int rockchip_pcie_init_port(struct udevice *dev)
>   	writel(PCIE_CLIENT_LINK_TRAIN_ENABLE,
>   	       priv->apb_base + PCIE_CLIENT_CONFIG);
>   
> -	if (dm_gpio_is_valid(&priv->ep_gpio))
> -		dm_gpio_set_value(&priv->ep_gpio, 1);
> +	if (dm_gpio_is_valid(&priv->ep_gpio)) {
> +		dm_gpio_set_dir_flags(&priv->ep_gpio, (priv->ep_gpio.flags & ~GPIOD_IS_OUT) | GPIOD_IS_IN);
> +		dm_gpio_set_dir_flags(&priv->ep_gpio, (priv->ep_gpio.flags & ~GPIOD_IS_IN) | GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
> +	}
>   
>   	ret = readl_poll_sleep_timeout
>   			(priv->apb_base + PCIE_CLIENT_BASIC_STATUS1,
> 
> So my report suggests this is not specific to Linux and because same
> workaround works in U-boot simplified driver model I suggest you check
> from your side.
> 
> Previously PCIe link training timeout, not working. Now I'm very happy
> with working PCIe in Linux and U-boot.
> 
> Thanks,
> Geraldo Nascimento
>