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From: Geraldo Nascimento <geraldogabriel@gmail.com>
To: "Shawn Lin" <shawn.lin@rock-chips.com>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
	"Manivannan Sadhasivam" <mani@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Johan Jonker" <jbx6244@gmail.com>,
	"Geraldo Nascimento" <geraldogabriel@gmail.com>,
	"Dragan Simic" <dsimic@manjaro.org>
Cc: linux-rockchip@lists.infradead.org, linux-pci@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: [PATCH v2 0/4] PCI: rockchip: 5.0 GT/s speed may be dangerous
Date: Mon, 17 Nov 2025 18:46:43 -0300	[thread overview]
Message-ID: <cover.1763415705.git.geraldogabriel@gmail.com> (raw)

Dragan Simic already had warned me of potential issues with 5.0 GT/s
speed operation in Rockchip PCIe. However, in recent interactions
with Shawn Lin from Rockchip it came to my attention there's grave
danger in the unknown errata regarding 5.0 GT/s operational speed
of their PCIe core. Even if the odds are low, to contain any damage,
let's cover the remaining corner-cases where the default would lead
to 5.0 GT/s operation as well as add a comment to Root Complex driver
core, documenting this danger. Furthermore, remove redundant
declaration of max-link-speed from rk3399-nanopi-r4s.dtsi

Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>

---

Changes in v2:
- hard limit to 2.5 GT/s, not just warn
- add Reported-by: and Reviewed-by: Dragan Simic
- remove redundant declaration of max-link-speed from helios64 dts
- fix Link: of helios64 patch
- simplify RC mode comment
- Link to v1: https://lore.kernel.org/all/aRhR79u5BPtRRFw3@geday/

Geraldo Nascimento (4):
  PCI: rockchip: limit RK3399 to 2.5 GT/s to prevent damage
  PCI: rockchip-host: comment danger of 5.0 GT/s speed
  arm64: dts: rockchip: remove dangerous max-link-speed from helios64
  arm64: dts: rockchip: remove redundant max-link-speed from nanopi-r4s

 arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts |  1 -
 arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dtsi    |  1 -
 drivers/pci/controller/pcie-rockchip-host.c            |  3 +++
 drivers/pci/controller/pcie-rockchip.c                 | 10 ++++++++--
 4 files changed, 11 insertions(+), 4 deletions(-)

-- 
2.49.0


             reply	other threads:[~2025-11-17 21:46 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-17 21:46 Geraldo Nascimento [this message]
2025-11-17 21:47 ` [PATCH v2 1/4] PCI: rockchip: limit RK3399 to 2.5 GT/s to prevent damage Geraldo Nascimento
2025-11-17 21:47 ` [PATCH v2 2/4] PCI: rockchip-host: comment danger of 5.0 GT/s speed Geraldo Nascimento
2025-11-17 21:47 ` [PATCH v2 3/4] arm64: dts: rockchip: remove dangerous max-link-speed from helios64 Geraldo Nascimento
2025-11-17 21:47 ` [PATCH v2 4/4] arm64: dts: rockchip: remove redundant max-link-speed from nanopi-r4s Geraldo Nascimento
2025-11-18  0:43 ` [PATCH v2 0/4] PCI: rockchip: 5.0 GT/s speed may be dangerous Shawn Lin
  -- strict thread matches above, loose matches on Subject: below --
2025-11-18  6:45 Dragan Simic
2025-11-18  7:17 ` Geraldo Nascimento

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