pcie_init() invokes pcie_disable_notification() for empty slots, which in
turn disables the Command Complete interrupt (unset PCI_EXP_SLTCTL_CCIE)
and right after that waits for Command Complete event (PCI_EXP_SLTSTA_CC).
Add a quirk for the PLX 8796 switch, which after disabling CCIE also stops
setting the PCI_EXP_SLTSTA_CC bit.
This quirk fixes the longer boot time - 4 seconds of delay for each empty
slot:
[ 4.200325] pciehp 0042:04:08.0:pcie204: Slot #40 AttnBtn+ PwrCtrl+ MRL- AttnInd+ PwrInd+ HotPlug+ Surprise- Interlock- NoCompl- LLActRep+
[ 4.200607] pciehp 0042:04:08.0:pcie204: pciehp_get_power_status: SLOTCTRL 80 value read 1c0
[ 6.217938] pciehp 0042:04:08.0:pcie204: Timeout on hotplug command 0x01c0 (issued 2020 msec ago)
[ 6.217966] pciehp 0042:04:08.0:pcie204: pcie_disable_notification: SLOTCTRL 80 write cmd 0
[ 6.237938] pciehp 0042:04:08.0:pcie204: Timeout on hotplug command 0x01c0 (issued 2040 msec ago)
[ 8.257939] pciehp 0042:04:08.0:pcie204: Timeout on hotplug command 0x05c0 (issued 2020 msec ago)
[ 8.257974] pciehp 0042:04:08.0:pcie204: pciehp_power_off_slot: SLOTCTRL 80 write cmd 400
[ 8.258034] pci_bus 0042:07: dev 00, created physical slot 40
[ 8.277941] pciehp 0042:04:08.0:pcie204: Timeout on hotplug command 0x05c0 (issued 2040 msec ago)
[ 8.277967] pciehp 0042:04:08.0:pcie204: pcie_enable_notification: SLOTCTRL 80 write cmd 1031
Cc: Lukas Wunner <lukas@xxxxxxxxx>
Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@xxxxxxxxx>
---
drivers/pci/hotplug/pciehp_hpc.c | 18 ++++++++++++++++++
include/linux/pci.h | 1 +
2 files changed, 19 insertions(+)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 1a522c1c4177..971258576be1 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -173,6 +173,10 @@ static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
(slot_ctrl_orig & CC_ERRATUM_MASK) == (slot_ctrl & CC_ERRATUM_MASK))
ctrl->cmd_busy = 0;
+ if (pdev->no_cmd_compl_wo_ccie &&
+ !(ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE))
+ ctrl->cmd_busy = 0;
+
/*
* Optionally wait for the hardware to be ready for a new command,
* indicating completion of the above issued command.
@@ -901,6 +905,18 @@ static void quirk_cmd_compl(struct pci_dev *pdev)
pdev->broken_cmd_compl = 1;
}
}
+
+static void quirk_no_cmd_compl_wo_ccie(struct pci_dev *pdev)
+{
+ u32 slot_cap;
+
+ if (pci_is_pcie(pdev)) {
+ pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
+ if (slot_cap & PCI_EXP_SLTCAP_HPC &&
+ !(slot_cap & PCI_EXP_SLTCAP_NCCS))
+ pdev->no_cmd_compl_wo_ccie = 1;
+ }
+}
DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400,
@@ -909,3 +925,5 @@ DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0401,
PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_HXT, 0x0401,
PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_PLX, 0x8796,
+ PCI_CLASS_BRIDGE_PCI, 8, quirk_no_cmd_compl_wo_ccie);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b5821134bdae..e61b92a15b19 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -437,6 +437,7 @@ struct pci_dev {
#ifdef CONFIG_HOTPLUG_PCI_PCIE
unsigned int broken_cmd_compl:1; /* No compl for some cmds */
+ unsigned int no_cmd_compl_wo_ccie:1; /* No compl if CCIE is unset */
#endif
#ifdef CONFIG_PCIE_PTM
unsigned int ptm_root:1;
--
2.23.0
