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Date:   Wed, 6 Dec 2023 11:26:40 -0700
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Subject: Re: [RESEND PATCH] arm64: dts: rockchip: Add PCIe pinctrls to Turing
 RK1
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To:     =?UTF-8?Q?Heiko_St=c3=bcbner?= <heiko@sntech.de>,
        Rob Herring <robh+dt@kernel.org>
Cc:     linux-rockchip@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org,
        =?UTF-8?Q?Daniel_Kukie=c5=82a?= <daniel@kukiela.pl>,
        Sven Rademakers <sven.rademakers@gmail.com>,
        Joshua Riek <jjriek@verizon.net>
References: <20231205202900.4617-1-CFSworks@gmail.com>
 <3331042.e9J7NaK4W3@diego>
From:   Sam Edwards <cfsworks@gmail.com>
In-Reply-To: <3331042.e9J7NaK4W3@diego>
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On 12/6/23 07:55, Heiko Stübner wrote:
> Am Dienstag, 5. Dezember 2023, 21:28:59 CET schrieb Sam Edwards:
>> The RK3588 PCIe 3.0 controller seems to have unpredictable behavior when
>> no CLKREQ/PERST/WAKE pins are configured in the pinmux. In particular, it
>> will sometimes (varying between specific RK3588 chips, not over time) shut
>> off the DBI block, and reads to this range will instead stall
>> indefinitely.
>>
>> When this happens, it will prevent Linux from booting altogether. The
>> PCIe driver will stall the CPU core once it attempts to read the version
>> information from the DBI range.
>>
>> Fix this boot hang by adding the correct pinctrl configuration to the
>> PCIe 3.0 device node, which is the proper thing to do anyway. While
>> we're at it, also add the necessary configuration to the PCIe 2.0 node,
>> which may or may not fix the equivalent problem over there -- but is the
>> proper thing to do anyway. :)
>>
>> Fixes: 2806a69f3fef6 ("arm64: dts: rockchip: Add Turing RK1 SoM support")
>> Signed-off-by: Sam Edwards <CFSworks@gmail.com>
>> ---
>>   .../arm64/boot/dts/rockchip/rk3588-turing-rk1.dtsi | 14 ++------------
>>   1 file changed, 2 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/rockchip/rk3588-turing-rk1.dtsi b/arch/arm64/boot/dts/rockchip/rk3588-turing-rk1.dtsi
>> index 9570b34aca2e..129f14dbd42f 100644
>> --- a/arch/arm64/boot/dts/rockchip/rk3588-turing-rk1.dtsi
>> +++ b/arch/arm64/boot/dts/rockchip/rk3588-turing-rk1.dtsi
>> @@ -214,7 +214,7 @@ rgmii_phy: ethernet-phy@1 {
>>   &pcie2x1l1 {
>>   	linux,pci-domain = <1>;
>>   	pinctrl-names = "default";
>> -	pinctrl-0 = <&pcie2_reset>;
>> +	pinctrl-0 = <&pcie30x1m1_pins>;
>>   	reset-gpios = <&gpio4 RK_PA2 GPIO_ACTIVE_HIGH>;
>>   	status = "okay";
>>   };
>> @@ -226,7 +226,7 @@ &pcie30phy {
>>   &pcie3x4 {
>>   	linux,pci-domain = <0>;
>>   	pinctrl-names = "default";
>> -	pinctrl-0 = <&pcie3_reset>;
>> +	pinctrl-0 = <&pcie30x4m1_pins>;

Hi Heiko,

> 
> also, why are you throwing out the pinctrl for the reset pin.
> That seems not related to the regular pins and you could instead just do
> 
> +	pinctrl-0 = <&pcie30x4m1_pins>, <&pcie3_reset>;

The pcie30x4m1_pins def does include pinmuxing `4 RK_PB6` to the DW 
controller already. The v2 patch should probably instead remove the 
reset-gpios property, since an out-of-band GPIO reset is not needed when 
the controller can do it.

I'm still looking into the story with the PCIe 2.0 pins, since 2.0x1's 
PERST# is definitely 4A2. I'll ask around and try to find out where the 
corresponding CLKREQ# is going.

> 
> Thanks
> Heiko

Likewise,
Sam

> 
>>   	reset-gpios = <&gpio4 RK_PB6 GPIO_ACTIVE_HIGH>;
>>   	vpcie3v3-supply = <&vcc3v3_pcie30>;
>>   	status = "okay";
>> @@ -245,17 +245,7 @@ hym8563_int: hym8563-int {
>>   		};
>>   	};
>>   
>> -	pcie2 {
>> -		pcie2_reset: pcie2-reset {
>> -			rockchip,pins = <4 RK_PA2 RK_FUNC_GPIO &pcfg_pull_none>;
>> -		};
>> -	};
>> -
>>   	pcie3 {
>> -		pcie3_reset: pcie3-reset {
>> -			rockchip,pins = <4 RK_PB6 RK_FUNC_GPIO &pcfg_pull_none>;
>> -		};
>> -
>>   		vcc3v3_pcie30_en: pcie3-reg {
>>   			rockchip,pins = <2 RK_PC5 RK_FUNC_GPIO &pcfg_pull_none>;
>>   		};
>>
> 
> 
> 
>