From: "Alex G." <mr.nuke.me@gmail.com>
To: Bjorn Helgaas <helgaas@kernel.org>
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,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] PCI/LINK: bw_notification: Do not leave interrupt handler NULL
Date: Mon, 25 Mar 2019 17:26:23 -0500 [thread overview]
Message-ID: <2dce09cf-dba2-2b2a-412d-40a546d9e2ac@gmail.com> (raw)
In-Reply-To: <20190325222502.GC24180@google.com>
On 3/25/19 5:25 PM, Bjorn Helgaas wrote:
> On Fri, Mar 22, 2019 at 07:36:51PM -0500, Alexandru Gagniuc wrote:
>> 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>
>
> Applied with the following subject line to for-linus for v5.1, thanks!
>
> PCI/LINK: Supply IRQ handler so level-triggered IRQs are acked
You're so much better at formulating commit messages. That sounds a lot
smoother. Thanks!
>> ---
>> 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:[~2019-03-25 22:26 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 ` [PATCH v2] " Alexandru Gagniuc
2019-03-25 22:25 ` Bjorn Helgaas
2019-03-25 22:26 ` Alex G. [this message]
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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