7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Geraldo Nascimento [ Upstream commit 7f173bfa6d42742de4ab647e001232c1165ab28e ] Drop the 5.0 GT/s Link Speed retraining code block from Rockchip PCIe EP driver. The reason is that Shawn Lin from Rockchip has reiterated that there may be danger of "catastrophic failure" in using their PCIe with 5.0 GT/s speeds. While Rockchip has done so informally without issuing a proper errata, and the particulars are thus unknown, this may cause data loss or worse. This change is corroborated by RK3399 official datasheet [1], which states maximum link speed for this platform is 2.5 GT/s. [1] https://opensource.rock-chips.com/images/d/d7/Rockchip_RK3399_Datasheet_V2.1-20200323.pdf Fixes: bd6e61df4b2e ("PCI: rockchip-ep: Improve link training") Reported-by: Dragan Simic Reported-by: Shawn Lin Link: https://lore.kernel.org/all/ffd05070-9879-4468-94e3-b88968b4c21b@rock-chips.com/ Signed-off-by: Geraldo Nascimento Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Reviewed-by: Dragan Simic Reviewed-by: Shawn Lin Cc: stable@vger.kernel.org Link: https://patch.msgid.link/d994f8fb3481bbb8f3972f117334a6e8aea383fb.1781622998.git.geraldogabriel@gmail.com Signed-off-by: Sasha Levin --- drivers/pci/controller/pcie-rockchip-ep.c | 13 ------------- 1 file changed, 13 deletions(-) diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c index 799461335762e..9ebc227a1ef84 100644 --- a/drivers/pci/controller/pcie-rockchip-ep.c +++ b/drivers/pci/controller/pcie-rockchip-ep.c @@ -553,19 +553,6 @@ static void rockchip_pcie_ep_link_training(struct work_struct *work) if (ret) goto again; - /* - * Check the current speed: if gen2 speed was requested and we are not - * at gen2 speed yet, retrain again for gen2. - */ - val = rockchip_pcie_read(rockchip, PCIE_CORE_CTRL); - if (!PCIE_LINK_IS_GEN2(val) && rockchip->link_gen == 2) { - /* Enable retrain for gen2 */ - rockchip_pcie_ep_retrain_link(rockchip); - readl_poll_timeout(rockchip->apb_base + PCIE_CORE_CTRL, - val, PCIE_LINK_IS_GEN2(val), 50, - LINK_TRAIN_TIMEOUT); - } - /* Check again that the link is up */ if (!rockchip_pcie_ep_link_up(rockchip)) goto again; -- 2.53.0