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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-pci@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH] PCI: Remove WARN_ON(in_interrupt()).
Date: Mon,  8 Feb 2021 20:44:00 +0100	[thread overview]
Message-ID: <20210208194400.384003-1-bigeasy@linutronix.de> (raw)

WARN_ON(in_interrupt()) is used for historic reasons to ensure proper
usage of down_read() and predates might_sleep() and lockdep.

down_read() has might_sleep() which also catches users from preemption
disabled regions while in_interrupt() does not.

Remove WARN_ON(in_interrupt()) because there is better debugging
facility.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/pci/search.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 2061672954ee3..b4c138a6ec025 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -168,7 +168,6 @@ struct pci_bus *pci_find_next_bus(const struct pci_bus *from)
 	struct list_head *n;
 	struct pci_bus *b = NULL;
 
-	WARN_ON(in_interrupt());
 	down_read(&pci_bus_sem);
 	n = from ? from->node.next : pci_root_buses.next;
 	if (n != &pci_root_buses)
@@ -196,7 +195,6 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
 {
 	struct pci_dev *dev;
 
-	WARN_ON(in_interrupt());
 	down_read(&pci_bus_sem);
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
@@ -274,7 +272,6 @@ static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
 	struct device *dev_start = NULL;
 	struct pci_dev *pdev = NULL;
 
-	WARN_ON(in_interrupt());
 	if (from)
 		dev_start = &from->dev;
 	dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
@@ -381,7 +378,6 @@ int pci_dev_present(const struct pci_device_id *ids)
 {
 	struct pci_dev *found = NULL;
 
-	WARN_ON(in_interrupt());
 	while (ids->vendor || ids->subvendor || ids->class_mask) {
 		found = pci_get_dev_by_id(ids, NULL);
 		if (found) {
-- 
2.30.0


             reply	other threads:[~2021-02-08 19:45 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-08 19:44 Sebastian Andrzej Siewior [this message]
2021-02-10 23:01 ` [PATCH] PCI: Remove WARN_ON(in_interrupt()) Bjorn Helgaas

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