[PATCH v2 2/4] PCI: rockchip-host: comment danger of 5.0 GT/s speed

Geraldo Nascimento
2025-11-17T21:47:39Z

According to Rockchip sources, there is grave danger in enabling 5.0
GT/s speed for this core. Add a comment documenting that danger and
discouraging end-users from forcing higher speed.

Link: https://lore.kernel.org/all/ffd05070-9879-4468-94e3-b88968b4c21b@rock-chips.com/
Cc: stable@vger.kernel.org
Reported-by: Dragan Simic <dsimic@manjaro.org>
Reported-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
---
drivers/pci/controller/pcie-rockchip-host.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
index ee1822ca01db..0af550277ee5 100644
--- a/drivers/pci/controller/pcie-rockchip-host.c
+++ b/drivers/pci/controller/pcie-rockchip-host.c
@@ -332,6 +332,9 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip)
/*
* Enable retrain for gen2. This should be configured only after
* gen1 finished.
+ *
+ * Dangerous and may lead to catastrophic failure eventually!
+ *
*/
status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_CR + PCI_EXP_LNKCTL2);
status &= ~PCI_EXP_LNKCTL2_TLS;
--
2.49.0