[pve-devel] [PATCH kernel] add fix for regression causing broken power indicators/LEDs

[Fiona Ebner]

The issue was reported in the enterprise support. The customer
contacted the ledmon maintainer, who found that it is not an issue
with ledmon, bisected the kernel and came up with this fix.

Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---
 ...n-Power-Indicator-bits-for-userspace.patch | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 patches/kernel/0021-PCI-pciehp-Retain-Power-Indicator-bits-for-userspace.patch

diff --git a/patches/kernel/0021-PCI-pciehp-Retain-Power-Indicator-bits-for-userspace.patch b/patches/kernel/0021-PCI-pciehp-Retain-Power-Indicator-bits-for-userspace.patch
new file mode 100644
index 0000000..7b94bcf
--- /dev/null
+++ b/patches/kernel/0021-PCI-pciehp-Retain-Power-Indicator-bits-for-userspace.patch
@@ -0,0 +1,56 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Blazej Kucman <blazej.kucman at intel.com>
+Date: Mon, 22 Jul 2024 16:14:40 +0200
+Subject: [PATCH] PCI: pciehp: Retain Power Indicator bits for userspace
+ indicators
+
+The sysfs "attention" file normally controls the Slot Control Attention
+Indicator with 0 (off), 1 (on), 2 (blink) settings.
+
+576243b3f9ea ("PCI: pciehp: Allow exclusive userspace control of
+indicators") added pciehp_set_raw_indicator_status() to allow userspace to
+directly control all four bits in both the Attention Indicator and the
+Power Indicator fields via the "attention" file.
+
+This is used on Intel VMD bridges so utilities like "ledmon" can use sysfs
+"attention" to control up to 16 indicators for NVMe device RAID status.
+
+abaaac4845a0 ("PCI: hotplug: Use FIELD_GET/PREP()") broke this by masking
+the sysfs data with PCI_EXP_SLTCTL_AIC, which discards the upper two bits
+intended for the Power Indicator Control field (PCI_EXP_SLTCTL_PIC).
+
+For NVMe devices behind an Intel VMD, ledmon settings that use the
+PCI_EXP_SLTCTL_PIC bits, i.e., ATTENTION_REBUILD (0x5), ATTENTION_LOCATE
+(0x7), ATTENTION_FAILURE (0xD), ATTENTION_OFF (0xF), no longer worked
+correctly.
+
+Mask with PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC to retain both the
+Attention Indicator and the Power Indicator bits.
+
+Fixes: abaaac4845a0 ("PCI: hotplug: Use FIELD_GET/PREP()")
+Link: https://lore.kernel.org/r/20240722141440.7210-1-blazej.kucman@intel.com
+Signed-off-by: Blazej Kucman <blazej.kucman at intel.com>
+[bhelgaas: commit log]
+Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
+Cc: stable at vger.kernel.org	# v6.7+
+(picked from https://lore.kernel.org/linux-pci/20240722141440.7210-1-blazej.kucman@intel.com/T/#u)
+Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
+---
+ drivers/pci/hotplug/pciehp_hpc.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
+index b1d0a1b3917d..9d3c249207c4 100644
+--- a/drivers/pci/hotplug/pciehp_hpc.c
++++ b/drivers/pci/hotplug/pciehp_hpc.c
+@@ -485,7 +485,9 @@ int pciehp_set_raw_indicator_status(struct hotplug_slot *hotplug_slot,
+ 	struct pci_dev *pdev = ctrl_dev(ctrl);
+ 
+ 	pci_config_pm_runtime_get(pdev);
+-	pcie_write_cmd_nowait(ctrl, FIELD_PREP(PCI_EXP_SLTCTL_AIC, status),
++
++	/* Attention and Power Indicator Control bits are supported */
++	pcie_write_cmd_nowait(ctrl, FIELD_PREP(PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC, status),
+ 			      PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC);
+ 	pci_config_pm_runtime_put(pdev);
+ 	return 0;
-- 
2.39.2