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From: Geraldo Nascimento <geraldogabriel@gmail.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: linux-rockchip@lists.infradead.org,
	"Shawn Lin" <shawn.lin@rock-chips.com>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Vinod Koul" <vkoul@kernel.org>,
	"Kishon Vijay Abraham I" <kishon@kernel.org>,
	linux-phy@lists.infradead.org, linux-pci@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 1/4] PCI: pcie-rockchip: add bits for Target Link Speed in LCS_2
Date: Wed, 11 Jun 2025 00:46:03 -0300	[thread overview]
Message-ID: <aEj7-6fMGKSXQb3J@geday> (raw)
In-Reply-To: <20250610200744.GA820589@bhelgaas>

On Tue, Jun 10, 2025 at 03:07:44PM -0500, Bjorn Helgaas wrote:
> On Sat, Jun 07, 2025 at 08:00:54AM -0300, Geraldo Nascimento wrote:
> This stuff:
> 
>   #define PCIE_RC_CONFIG_DCR              (PCIE_RC_CONFIG_BASE + 0xc4)
>   #define PCIE_RC_CONFIG_DCSR             (PCIE_RC_CONFIG_BASE + 0xc8)
>   #define PCIE_RC_CONFIG_LINK_CAP         (PCIE_RC_CONFIG_BASE + 0xcc)
>   #define PCIE_RC_CONFIG_LCS              (PCIE_RC_CONFIG_BASE + 0xd0)
>   #define PCIE_RC_CONFIG_LCS_2            (PCIE_RC_CONFIG_BASE + 0xf0)
> 
> *Looks* like it might be duplicates of:
> 
>   #define PCI_EXP_DEVCAP          0x04    /* Device capabilities */
>   #define PCI_EXP_DEVCTL          0x08    /* Device Control */
>   #define PCI_EXP_LNKCAP          0x0c    /* Link Capabilities */

Hi again Bjorn,

Your message reminded me of something that may be important.

During my debugging I had the mild impression L0s capability is not
being cleared from Link Capabilities Register in the presence of
"aspm-no-l0s" DT property.

I can't confirm it right now but I might revisit this later on. From
what I've seen it can only be cleared from inside the port init
in pcie-rockchip.c and does nothing in present form.

Not a clear, confirmable report but something to watch out for...

Regards,
Geraldo Nascimento


  parent reply	other threads:[~2025-06-11  3:56 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-07 11:00 [RFC PATCH 1/4] PCI: pcie-rockchip: add bits for Target Link Speed in LCS_2 Geraldo Nascimento
2025-06-10 20:07 ` Bjorn Helgaas
2025-06-10 20:09   ` Geraldo Nascimento
2025-06-11  3:46   ` Geraldo Nascimento [this message]
2025-06-11  3:59     ` Geraldo Nascimento

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