From: Feng Tang Date: Mon, 3 Mar 2025 02:36:30 +0000 (+0800) Subject: PCI/portdrv: Only disable pciehp interrupts early when needed X-Git-Tag: block-6.15-20250403~40^2~26^2~2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=9d7db4db19827380e225914618c0c1bf435ed2f5;p=linux-block.git PCI/portdrv: Only disable pciehp interrupts early when needed Firmware developers reported that Linux issues two PCIe hotplug commands in very short intervals on an ARM server, which doesn't comply with the PCIe spec. According to PCIe r6.1, sec 6.7.3.2, if the Command Completed event is supported, software must wait for a command to complete or wait at least 1 second before sending a new command. In the failure case, the first PCIe hotplug command is from get_port_device_capability(), which sends a command to disable PCIe hotplug interrupts without waiting for its completion, and the second command comes from pcie_enable_notification() of pciehp driver, which enables hotplug interrupts again. Fix this by only disabling the hotplug interrupts when the pciehp driver is not enabled. Link: https://lore.kernel.org/r/20250303023630.78397-1-feng.tang@linux.alibaba.com Fixes: 2bd50dd800b5 ("PCI: PCIe: Disable PCIe port services during port initialization") Suggested-by: Lukas Wunner Signed-off-by: Feng Tang [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Reviewed-by: Kuppuswamy Sathyanarayanan --- diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c index 02e73099bad0..e8318fd5f6ed 100644 --- a/drivers/pci/pcie/portdrv.c +++ b/drivers/pci/pcie/portdrv.c @@ -228,10 +228,12 @@ static int get_port_device_capability(struct pci_dev *dev) /* * Disable hot-plug interrupts in case they have been enabled - * by the BIOS and the hot-plug service driver is not loaded. + * by the BIOS and the hot-plug service driver won't be loaded + * to handle them. */ - pcie_capability_clear_word(dev, PCI_EXP_SLTCTL, - PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE); + if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) + pcie_capability_clear_word(dev, PCI_EXP_SLTCTL, + PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE); } #ifdef CONFIG_PCIEAER