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-rw-r--r--kernels/linux-libre-xtreme/0004-PCI-pciehp-Prevent-deadlock-on-disconnect.patch272
1 files changed, 0 insertions, 272 deletions
diff --git a/kernels/linux-libre-xtreme/0004-PCI-pciehp-Prevent-deadlock-on-disconnect.patch b/kernels/linux-libre-xtreme/0004-PCI-pciehp-Prevent-deadlock-on-disconnect.patch
deleted file mode 100644
index 69bcddb7a..000000000
--- a/kernels/linux-libre-xtreme/0004-PCI-pciehp-Prevent-deadlock-on-disconnect.patch
+++ /dev/null
@@ -1,272 +0,0 @@
-From 4c3a182e5ce8a05eb3db20b908a60015fb47d021 Mon Sep 17 00:00:00 2001
-From: Mika Westerberg <mika.westerberg@linux.intel.com>
-Date: Tue, 29 Oct 2019 20:00:22 +0300
-Subject: [PATCH 04/14] PCI: pciehp: Prevent deadlock on disconnect
-
-This addresses deadlocks in these common cases in hierarchies containing
-two switches:
-
- - All involved ports are runtime suspended and they are unplugged. This
- can happen easily if the drivers involved automatically enable runtime
- PM (xHCI for example does that).
-
- - System is suspended (e.g., closing the lid on a laptop) with a dock +
- something else connected, and the dock is unplugged while suspended.
-
-These cases lead to the following deadlock:
-
- INFO: task irq/126-pciehp:198 blocked for more than 120 seconds.
- irq/126-pciehp D 0 198 2 0x80000000
- Call Trace:
- schedule+0x2c/0x80
- schedule_timeout+0x246/0x350
- wait_for_completion+0xb7/0x140
- kthread_stop+0x49/0x110
- free_irq+0x32/0x70
- pcie_shutdown_notification+0x2f/0x50
- pciehp_remove+0x27/0x50
- pcie_port_remove_service+0x36/0x50
- device_release_driver+0x12/0x20
- bus_remove_device+0xec/0x160
- device_del+0x13b/0x350
- device_unregister+0x1a/0x60
- remove_iter+0x1e/0x30
- device_for_each_child+0x56/0x90
- pcie_port_device_remove+0x22/0x40
- pcie_portdrv_remove+0x20/0x60
- pci_device_remove+0x3e/0xc0
- device_release_driver_internal+0x18c/0x250
- device_release_driver+0x12/0x20
- pci_stop_bus_device+0x6f/0x90
- pci_stop_bus_device+0x31/0x90
- pci_stop_and_remove_bus_device+0x12/0x20
- pciehp_unconfigure_device+0x88/0x140
- pciehp_disable_slot+0x6a/0x110
- pciehp_handle_presence_or_link_change+0x263/0x400
- pciehp_ist+0x1c9/0x1d0
- irq_thread_fn+0x24/0x60
- irq_thread+0xeb/0x190
- kthread+0x120/0x140
-
- INFO: task irq/190-pciehp:2288 blocked for more than 120 seconds.
- irq/190-pciehp D 0 2288 2 0x80000000
- Call Trace:
- __schedule+0x2a2/0x880
- schedule+0x2c/0x80
- schedule_preempt_disabled+0xe/0x10
- mutex_lock+0x2c/0x30
- pci_lock_rescan_remove+0x15/0x20
- pciehp_unconfigure_device+0x4d/0x140
- pciehp_disable_slot+0x6a/0x110
- pciehp_handle_presence_or_link_change+0x263/0x400
- pciehp_ist+0x1c9/0x1d0
- irq_thread_fn+0x24/0x60
- irq_thread+0xeb/0x190
- kthread+0x120/0x140
-
-What happens here is that the whole hierarchy is runtime resumed and the
-parent PCIe downstream port, which got the hot-remove event, starts
-removing devices below it, taking pci_lock_rescan_remove() lock. When the
-child PCIe port is runtime resumed it calls pciehp_check_presence() which
-ends up calling pciehp_card_present() and pciehp_check_link_active(). Both
-of these use pcie_capability_read_word(), which notices that the underlying
-device is already gone and returns PCIBIOS_DEVICE_NOT_FOUND with the
-capability value set to 0. When pciehp gets this value it thinks that its
-child device is also hot-removed and schedules its IRQ thread to handle the
-event.
-
-The deadlock happens when the child's IRQ thread runs and tries to acquire
-pci_lock_rescan_remove() which is already taken by the parent and the
-parent waits for the child's IRQ thread to finish.
-
-Prevent this from happening by checking the return value of
-pcie_capability_read_word() and if it is PCIBIOS_DEVICE_NOT_FOUND stop
-performing any hot-removal activities.
-
-[bhelgaas: add common scenarios to commit log]
-Link: https://lore.kernel.org/r/20191029170022.57528-2-mika.westerberg@linux.intel.com
-Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
-Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
-Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
----
- drivers/pci/hotplug/pciehp.h | 6 ++--
- drivers/pci/hotplug/pciehp_core.c | 11 ++++--
- drivers/pci/hotplug/pciehp_ctrl.c | 4 +--
- drivers/pci/hotplug/pciehp_hpc.c | 59 +++++++++++++++++++++++++------
- 4 files changed, 61 insertions(+), 19 deletions(-)
-
-diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
-index 882ce82c4699..aa61d4c219d7 100644
---- a/drivers/pci/hotplug/pciehp.h
-+++ b/drivers/pci/hotplug/pciehp.h
-@@ -174,10 +174,10 @@ void pciehp_set_indicators(struct controller *ctrl, int pwr, int attn);
-
- void pciehp_get_latch_status(struct controller *ctrl, u8 *status);
- int pciehp_query_power_fault(struct controller *ctrl);
--bool pciehp_card_present(struct controller *ctrl);
--bool pciehp_card_present_or_link_active(struct controller *ctrl);
-+int pciehp_card_present(struct controller *ctrl);
-+int pciehp_card_present_or_link_active(struct controller *ctrl);
- int pciehp_check_link_status(struct controller *ctrl);
--bool pciehp_check_link_active(struct controller *ctrl);
-+int pciehp_check_link_active(struct controller *ctrl);
- void pciehp_release_ctrl(struct controller *ctrl);
-
- int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
-diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
-index 56daad828c9e..312cc45c44c7 100644
---- a/drivers/pci/hotplug/pciehp_core.c
-+++ b/drivers/pci/hotplug/pciehp_core.c
-@@ -139,10 +139,15 @@ static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
- {
- struct controller *ctrl = to_ctrl(hotplug_slot);
- struct pci_dev *pdev = ctrl->pcie->port;
-+ int ret;
-
- pci_config_pm_runtime_get(pdev);
-- *value = pciehp_card_present_or_link_active(ctrl);
-+ ret = pciehp_card_present_or_link_active(ctrl);
- pci_config_pm_runtime_put(pdev);
-+ if (ret < 0)
-+ return ret;
-+
-+ *value = ret;
- return 0;
- }
-
-@@ -158,13 +163,13 @@ static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
- */
- static void pciehp_check_presence(struct controller *ctrl)
- {
-- bool occupied;
-+ int occupied;
-
- down_read(&ctrl->reset_lock);
- mutex_lock(&ctrl->state_lock);
-
- occupied = pciehp_card_present_or_link_active(ctrl);
-- if ((occupied && (ctrl->state == OFF_STATE ||
-+ if ((occupied > 0 && (ctrl->state == OFF_STATE ||
- ctrl->state == BLINKINGON_STATE)) ||
- (!occupied && (ctrl->state == ON_STATE ||
- ctrl->state == BLINKINGOFF_STATE)))
-diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
-index dd8e4a5fb282..6503d15effbb 100644
---- a/drivers/pci/hotplug/pciehp_ctrl.c
-+++ b/drivers/pci/hotplug/pciehp_ctrl.c
-@@ -226,7 +226,7 @@ void pciehp_handle_disable_request(struct controller *ctrl)
-
- void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
- {
-- bool present, link_active;
-+ int present, link_active;
-
- /*
- * If the slot is on and presence or link has changed, turn it off.
-@@ -257,7 +257,7 @@ void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
- mutex_lock(&ctrl->state_lock);
- present = pciehp_card_present(ctrl);
- link_active = pciehp_check_link_active(ctrl);
-- if (!present && !link_active) {
-+ if (present <= 0 && link_active <= 0) {
- mutex_unlock(&ctrl->state_lock);
- return;
- }
-diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
-index 86d97f3112f0..a2a263764ef8 100644
---- a/drivers/pci/hotplug/pciehp_hpc.c
-+++ b/drivers/pci/hotplug/pciehp_hpc.c
-@@ -201,17 +201,29 @@ static void pcie_write_cmd_nowait(struct controller *ctrl, u16 cmd, u16 mask)
- pcie_do_write_cmd(ctrl, cmd, mask, false);
- }
-
--bool pciehp_check_link_active(struct controller *ctrl)
-+/**
-+ * pciehp_check_link_active() - Is the link active
-+ * @ctrl: PCIe hotplug controller
-+ *
-+ * Check whether the downstream link is currently active. Note it is
-+ * possible that the card is removed immediately after this so the
-+ * caller may need to take it into account.
-+ *
-+ * If the hotplug controller itself is not available anymore returns
-+ * %-ENODEV.
-+ */
-+int pciehp_check_link_active(struct controller *ctrl)
- {
- struct pci_dev *pdev = ctrl_dev(ctrl);
- u16 lnk_status;
-- bool ret;
-+ int ret;
-
-- pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
-- ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
-+ ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
-+ if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)~0)
-+ return -ENODEV;
-
-- if (ret)
-- ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
-+ ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
-+ ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
-
- return ret;
- }
-@@ -373,13 +385,29 @@ void pciehp_get_latch_status(struct controller *ctrl, u8 *status)
- *status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
- }
-
--bool pciehp_card_present(struct controller *ctrl)
-+/**
-+ * pciehp_card_present() - Is the card present
-+ * @ctrl: PCIe hotplug controller
-+ *
-+ * Function checks whether the card is currently present in the slot and
-+ * in that case returns true. Note it is possible that the card is
-+ * removed immediately after the check so the caller may need to take
-+ * this into account.
-+ *
-+ * It the hotplug controller itself is not available anymore returns
-+ * %-ENODEV.
-+ */
-+int pciehp_card_present(struct controller *ctrl)
- {
- struct pci_dev *pdev = ctrl_dev(ctrl);
- u16 slot_status;
-+ int ret;
-
-- pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
-- return slot_status & PCI_EXP_SLTSTA_PDS;
-+ ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
-+ if (ret == PCIBIOS_DEVICE_NOT_FOUND || slot_status == (u16)~0)
-+ return -ENODEV;
-+
-+ return !!(slot_status & PCI_EXP_SLTSTA_PDS);
- }
-
- /**
-@@ -390,10 +418,19 @@ bool pciehp_card_present(struct controller *ctrl)
- * Presence Detect State bit, this helper also returns true if the Link Active
- * bit is set. This is a concession to broken hotplug ports which hardwire
- * Presence Detect State to zero, such as Wilocity's [1ae9:0200].
-+ *
-+ * Returns: %1 if the slot is occupied and %0 if it is not. If the hotplug
-+ * port is not present anymore returns %-ENODEV.
- */
--bool pciehp_card_present_or_link_active(struct controller *ctrl)
-+int pciehp_card_present_or_link_active(struct controller *ctrl)
- {
-- return pciehp_card_present(ctrl) || pciehp_check_link_active(ctrl);
-+ int ret;
-+
-+ ret = pciehp_card_present(ctrl);
-+ if (ret)
-+ return ret;
-+
-+ return pciehp_check_link_active(ctrl);
- }
-
- int pciehp_query_power_fault(struct controller *ctrl)
---
-2.25.0
-
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-03 23:43:05 +0000