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From: Damien Le Moal <dlemoal@kernel.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: "Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Kishon Vijay Abraham I" <kishon@kernel.org>,
	"Shawn Lin" <shawn.lin@rock-chips.com>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	linux-pci@vger.kernel.org, "Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Heiko Stuebner" <heiko@sntech.de>,
	devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org,
	"Rick Wertenbroek" <rick.wertenbroek@gmail.com>,
	"Niklas Cassel" <cassel@kernel.org>
Subject: Re: [PATCH v5 12/14] PCI: rockchip-ep: Improve link training
Date: Sun, 17 Nov 2024 17:00:42 +0900	[thread overview]
Message-ID: <8393e56d-8ba1-436d-ad97-ec44893d2f6f@kernel.org> (raw)
In-Reply-To: <20241115230319.GA2065576@bhelgaas>

On 11/16/24 08:03, Bjorn Helgaas wrote:
> On Thu, Oct 17, 2024 at 10:58:47AM +0900, Damien Le Moal wrote:
>> The Rockchip RK3399 TRM V1.3 Part2, Section 17.5.8.1.2, step 7,
>> describes the endpoint mode link training process clearly and states
>> that:
>>   Insure link training completion and success by observing link_st field
>>   in PCIe Client BASIC_STATUS1 register change to 2'b11. If both side
>>   support PCIe Gen2 speed, re-train can be Initiated by asserting the
>>   Retrain Link field in Link Control and Status Register. The software
>>   should insure the BASIC_STATUS0[negotiated_speed] changes to "1", that
>>   indicates re-train to Gen2 successfully.
> 
> Since this only adds code and doesn't change existing code, I assume
> this hardware doesn't automatically train to gen2 without this new
> software assistance?
> 
> So the effect of this change is to use gen2 speed when supported by
> both partners, when previously we only got gen1?

Yes. The host side has something similar as well.


-- 
Damien Le Moal
Western Digital Research

  reply	other threads:[~2024-11-17  8:00 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-17  1:58 [PATCH v5 00/14] Fix and improve the Rockchip endpoint driver Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 01/14] PCI: rockchip-ep: Fix address translation unit programming Damien Le Moal
2024-11-15 22:41   ` Bjorn Helgaas
2024-11-17  8:04     ` Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 02/14] PCI: rockchip-ep: Use a macro to define EP controller .align feature Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 03/14] PCI: rockchip-ep: Improve rockchip_pcie_ep_unmap_addr() Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 04/14] PCI: rockchip-ep: Improve rockchip_pcie_ep_map_addr() Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 05/14] PCI: rockchip-ep: Implement the pci_epc_ops::align_addr() operation Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 06/14] PCI: rockchip-ep: Fix MSI IRQ data mapping Damien Le Moal
2024-10-17  9:52   ` Niklas Cassel
2024-10-17  1:58 ` [PATCH v5 07/14] PCI: rockchip-ep: Rename rockchip_pcie_parse_ep_dt() Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 08/14] PCI: rockchip-ep: Refactor rockchip_pcie_ep_probe() memory allocations Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 09/14] PCI: rockchip-ep: Refactor rockchip_pcie_ep_probe() MSI-X hiding Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 10/14] PCI: rockchip-ep: Refactor endpoint link training enable Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 11/14] PCI: rockship-ep: Implement the pci_epc_ops::stop_link() operation Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 12/14] PCI: rockchip-ep: Improve link training Damien Le Moal
2024-11-15 23:03   ` Bjorn Helgaas
2024-11-17  8:00     ` Damien Le Moal [this message]
2024-10-17  1:58 ` [PATCH v5 13/14] PCI: rockchip-ep: Handle PERST# signal in endpoint mode Damien Le Moal
2024-12-15  0:13   ` Bjorn Helgaas
2024-12-15  2:09     ` Damien Le Moal
2024-10-17  1:58 ` [PATCH v5 14/14] arm64: dts: rockchip: Add rockpro64 overlay for PCIe " Damien Le Moal
2024-10-29 10:35 ` [PATCH v5 00/14] Fix and improve the Rockchip endpoint driver Damien Le Moal
2024-11-13 14:29   ` Damien Le Moal
2024-11-13 17:52     ` Manivannan Sadhasivam
2024-11-13 20:59       ` Krzysztof Wilczyński
2024-11-14  4:14         ` Damien Le Moal
2024-11-14 17:24           ` Krzysztof Wilczyński
2024-11-13 20:49 ` Krzysztof Wilczyński
2024-12-16  5:49 ` Manivannan Sadhasivam
2024-12-16  6:00   ` Niklas Cassel
2024-12-16  6:05     ` Manivannan Sadhasivam

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