From: Alexandru Gagniuc <mr.nuke.me@gmail.com>
To: bhelgaas@google.com
Cc: austin_bolen@dell.com, alex_gagniuc@dellteam.com,
keith.busch@intel.com, Shyam_Iyer@Dell.com, lukas@wunner.de,
okaya@kernel.org, torvalds@linux-foundation.org,
Alexandru Gagniuc <mr.nuke.me@gmail.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] PCI/LINK: bw_notification: Do not leave interrupt handler NULL
Date: Fri, 22 Mar 2019 19:36:51 -0500 [thread overview]
Message-ID: <20190323003700.7294-1-mr.nuke.me@gmail.com> (raw)
In-Reply-To: <20190320193504.GC251185@google.com>
A threaded IRQ with a NULL handler does not work with level-triggered
interrupts. request_threaded_irq() will return an error:
genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq 16
pcie_bw_notification: probe of 0000:00:1b.0:pcie010 failed with error -22
For level interrupts we need to silence the interrupt before exiting
the IRQ handler, so just clear the PCI_EXP_LNKSTA_LBMS bit there.
Fixes: e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth notification")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
---
Changes since v1:
- move pcie_update_link_speed() to irq to prevent duplicate read of link_status
- Add Fixes: to commit message
drivers/pci/pcie/bw_notification.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/pcie/bw_notification.c b/drivers/pci/pcie/bw_notification.c
index d2eae3b7cc0f..c48746f1cf3c 100644
--- a/drivers/pci/pcie/bw_notification.c
+++ b/drivers/pci/pcie/bw_notification.c
@@ -44,11 +44,10 @@ static void pcie_disable_link_bandwidth_notification(struct pci_dev *dev)
pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl);
}
-static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
+static irqreturn_t pcie_bw_notification_irq(int irq, void *context)
{
struct pcie_device *srv = context;
struct pci_dev *port = srv->port;
- struct pci_dev *dev;
u16 link_status, events;
int ret;
@@ -58,6 +57,17 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
if (ret != PCIBIOS_SUCCESSFUL || !events)
return IRQ_NONE;
+ pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
+ pcie_update_link_speed(port->subordinate, link_status);
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
+{
+ struct pcie_device *srv = context;
+ struct pci_dev *port = srv->port;
+ struct pci_dev *dev;
+
/*
* Print status from downstream devices, not this root port or
* downstream switch port.
@@ -67,8 +77,6 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
__pcie_print_link_status(dev, false);
up_read(&pci_bus_sem);
- pcie_update_link_speed(port->subordinate, link_status);
- pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
return IRQ_HANDLED;
}
@@ -80,7 +88,8 @@ static int pcie_bandwidth_notification_probe(struct pcie_device *srv)
if (!pcie_link_bandwidth_notification_supported(srv->port))
return -ENODEV;
- ret = request_threaded_irq(srv->irq, NULL, pcie_bw_notification_handler,
+ ret = request_threaded_irq(srv->irq, pcie_bw_notification_irq,
+ pcie_bw_notification_handler,
IRQF_SHARED, "PCIe BW notif", srv);
if (ret)
return ret;
--
2.19.2
next prev parent reply other threads:[~2019-03-23 0:37 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-08 17:31 [GIT PULL] PCI changes for v5.1 Bjorn Helgaas
2019-03-09 23:15 ` pr-tracker-bot
2019-03-17 21:18 ` Linus Torvalds
2019-03-18 0:22 ` Alex G
2019-03-18 4:33 ` Lukas Wunner
2019-03-19 1:12 ` [PATCH] PCI/LINK: bw_notification: Do not leave interrupt handler NULL Alexandru Gagniuc
2019-03-19 19:25 ` Lukas Wunner
2019-03-19 20:00 ` Keith Busch
2019-03-20 13:46 ` Bjorn Helgaas
2019-03-20 13:48 ` Alex G.
2019-03-20 19:35 ` Bjorn Helgaas
2019-03-23 0:36 ` Alexandru Gagniuc [this message]
2019-03-25 22:25 ` [PATCH v2] " Bjorn Helgaas
2019-03-25 22:26 ` Alex G.
2019-03-25 22:59 ` Bjorn Helgaas
2019-04-19 21:08 ` Alex Williamson
2019-04-19 21:25 ` Bjorn Helgaas
2019-04-22 21:11 ` Alex Williamson
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