The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x df27c03b9e3ef2baa9e9c9f56a771d463a84489d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2026011221-exploit-unglazed-3e32@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From df27c03b9e3ef2baa9e9c9f56a771d463a84489d Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas bhelgaas@google.com Date: Mon, 3 Nov 2025 16:19:26 -0600 Subject: [PATCH] PCI: meson: Report that link is up while in ASPM L0s and L1 states
Previously meson_pcie_link_up() only returned true if the link was in the L0 state. This was incorrect because hardware autonomously manages transitions between L0, L0s, and L1 while both components on the link stay in D0. Those states should all be treated as "link is active".
Returning false when the device was in L0s or L1 broke config accesses because dw_pcie_other_conf_map_bus() fails if the link is down, which caused errors like this:
meson-pcie fc000000.pcie: error: wait linkup timeout pci 0000:01:00.0: BAR 0: error updating (0xfc700004 != 0xffffffff)
Remove the LTSSM state check, timeout, speed check, and error message from meson_pcie_link_up(), the dw_pcie_ops.link_up() method, so it is a simple boolean check of whether the link is active. Timeouts and error messages are handled at a higher level, e.g., dw_pcie_wait_for_link().
Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver") Reported-by: Linnaea Lavia linnaea-von-lavia@live.com Closes: https://lore.kernel.org/r/DM4PR05MB102707B8CDF84D776C39F22F2C7F0A@DM4PR05MB1... [bhelgaas: squash removal of unused WAIT_LINKUP_TIMEOUT by Martin Blumenstingl martin.blumenstingl@googlemail.com: https://patch.msgid.link/20260105125625.239497-1-martin.blumenstingl@googlem...] Signed-off-by: Bjorn Helgaas bhelgaas@google.com Tested-by: Linnaea Lavia linnaea-von-lavia@live.com Tested-by: Neil Armstrong neil.armstrong@linaro.org # on BananaPi M2S Reviewed-by: Neil Armstrong neil.armstrong@linaro.org Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251103221930.1831376-1-helgaas@kernel.org Link: https://patch.msgid.link/20260105125625.239497-1-martin.blumenstingl@googlem...
diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c index 54b6a4196f17..0694084f612b 100644 --- a/drivers/pci/controller/dwc/pci-meson.c +++ b/drivers/pci/controller/dwc/pci-meson.c @@ -37,7 +37,6 @@ #define PCIE_CFG_STATUS17 0x44 #define PM_CURRENT_STATE(x) (((x) >> 7) & 0x1)
-#define WAIT_LINKUP_TIMEOUT 4000 #define PORT_CLK_RATE 100000000UL #define MAX_PAYLOAD_SIZE 256 #define MAX_READ_REQ_SIZE 256 @@ -350,40 +349,10 @@ static struct pci_ops meson_pci_ops = { static bool meson_pcie_link_up(struct dw_pcie *pci) { struct meson_pcie *mp = to_meson_pcie(pci); - struct device *dev = pci->dev; - u32 speed_okay = 0; - u32 cnt = 0; - u32 state12, state17, smlh_up, ltssm_up, rdlh_up; + u32 state12;
- do { - state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12); - state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17); - smlh_up = IS_SMLH_LINK_UP(state12); - rdlh_up = IS_RDLH_LINK_UP(state12); - ltssm_up = IS_LTSSM_UP(state12); - - if (PM_CURRENT_STATE(state17) < PCIE_GEN3) - speed_okay = 1; - - if (smlh_up) - dev_dbg(dev, "smlh_link_up is on\n"); - if (rdlh_up) - dev_dbg(dev, "rdlh_link_up is on\n"); - if (ltssm_up) - dev_dbg(dev, "ltssm_up is on\n"); - if (speed_okay) - dev_dbg(dev, "speed_okay\n"); - - if (smlh_up && rdlh_up && ltssm_up && speed_okay) - return true; - - cnt++; - - udelay(10); - } while (cnt < WAIT_LINKUP_TIMEOUT); - - dev_err(dev, "error: wait linkup timeout\n"); - return false; + state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12); + return IS_SMLH_LINK_UP(state12) && IS_RDLH_LINK_UP(state12); }
static int meson_pcie_host_init(struct dw_pcie_rp *pp)