5.10-stable patches

added patches:
	pci-pciehp-fix-infinite-loop-in-irq-handler-upon-power-fault.patch

diff --git a/queue-5.10/pci-pciehp-fix-infinite-loop-in-irq-handler-upon-power-fault.patch b/queue-5.10/pci-pciehp-fix-infinite-loop-in-irq-handler-upon-power-fault.patch
new file mode 100644 (file)
index 0000000..2c812af
--- /dev/null
+++ b/queue-5.10/pci-pciehp-fix-infinite-loop-in-irq-handler-upon-power-fault.patch
@@ -0,0 +1,76 @@
+From 23584c1ed3e15a6f4bfab8dc5a88d94ab929ee12 Mon Sep 17 00:00:00 2001
+From: Lukas Wunner <lukas@wunner.de>
+Date: Wed, 17 Nov 2021 23:22:09 +0100
+Subject: PCI: pciehp: Fix infinite loop in IRQ handler upon power fault
+
+From: Lukas Wunner <lukas@wunner.de>
+
+commit 23584c1ed3e15a6f4bfab8dc5a88d94ab929ee12 upstream.
+
+The Power Fault Detected bit in the Slot Status register differs from
+all other hotplug events in that it is sticky:  It can only be cleared
+after turning off slot power.  Per PCIe r5.0, sec. 6.7.1.8:
+
+  If a power controller detects a main power fault on the hot-plug slot,
+  it must automatically set its internal main power fault latch [...].
+  The main power fault latch is cleared when software turns off power to
+  the hot-plug slot.
+
+The stickiness used to cause interrupt storms and infinite loops which
+were fixed in 2009 by commits 5651c48cfafe ("PCI pciehp: fix power fault
+interrupt storm problem") and 99f0169c17f3 ("PCI: pciehp: enable
+software notification on empty slots").
+
+Unfortunately in 2020 the infinite loop issue was inadvertently
+reintroduced by commit 8edf5332c393 ("PCI: pciehp: Fix MSI interrupt
+race"):  The hardirq handler pciehp_isr() clears the PFD bit until
+pciehp's power_fault_detected flag is set.  That happens in the IRQ
+thread pciehp_ist(), which never learns of the event because the hardirq
+handler is stuck in an infinite loop.  Fix by setting the
+power_fault_detected flag already in the hardirq handler.
+
+Link: https://bugzilla.kernel.org/show_bug.cgi?id=214989
+Link: https://lore.kernel.org/linux-pci/DM8PR11MB5702255A6A92F735D90A4446868B9@DM8PR11MB5702.namprd11.prod.outlook.com
+Fixes: 8edf5332c393 ("PCI: pciehp: Fix MSI interrupt race")
+Link: https://lore.kernel.org/r/66eaeef31d4997ceea357ad93259f290ededecfd.1637187226.git.lukas@wunner.de
+Reported-by: Joseph Bao <joseph.bao@intel.com>
+Tested-by: Joseph Bao <joseph.bao@intel.com>
+Signed-off-by: Lukas Wunner <lukas@wunner.de>
+Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
+Cc: stable@vger.kernel.org # v4.19+
+Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/pci/hotplug/pciehp_hpc.c |    7 ++++---
+ 1 file changed, 4 insertions(+), 3 deletions(-)
+
+--- a/drivers/pci/hotplug/pciehp_hpc.c
++++ b/drivers/pci/hotplug/pciehp_hpc.c
+@@ -642,6 +642,8 @@ read_status:
+        */
+       if (ctrl->power_fault_detected)
+               status &= ~PCI_EXP_SLTSTA_PFD;
++      else if (status & PCI_EXP_SLTSTA_PFD)
++              ctrl->power_fault_detected = true;
+ 
+       events |= status;
+       if (!events) {
+@@ -651,7 +653,7 @@ read_status:
+       }
+ 
+       if (status) {
+-              pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events);
++              pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, status);
+ 
+               /*
+                * In MSI mode, all event bits must be zero before the port
+@@ -725,8 +727,7 @@ static irqreturn_t pciehp_ist(int irq, v
+       }
+ 
+       /* Check Power Fault Detected */
+-      if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
+-              ctrl->power_fault_detected = 1;
++      if (events & PCI_EXP_SLTSTA_PFD) {
+               ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
+               pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
+                                     PCI_EXP_SLTCTL_ATTN_IND_ON);

diff --git a/queue-5.10/series b/queue-5.10/series
new file mode 100644 (file)
index 0000000..1985dac
--- /dev/null
+++ b/queue-5.10/series
@@ -0,0 +1 @@
+pci-pciehp-fix-infinite-loop-in-irq-handler-upon-power-fault.patch