From: Lukas Wunner <lukas@wunner.de>
To: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Cc: bhelgaas@google.com, austin_bolen@dell.com,
alex_gagniuc@dellteam.com, keith.busch@intel.com,
Shyam_Iyer@Dell.com, okaya@kernel.org,
torvalds@linux-foundation.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI/LINK: bw_notification: Do not leave interrupt handler NULL
Date: Tue, 19 Mar 2019 20:25:50 +0100 [thread overview]
Message-ID: <20190319192550.5lxfm3h2jnaip3on@wunner.de> (raw)
In-Reply-To: <20190319011214.7847-1-mr.nuke.me@gmail.com>
On Mon, Mar 18, 2019 at 08:12:04PM -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.
>
> Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
I've tested this on my Ivy Bridge MacBook Pro which uses INTx on root and
downstream ports and I'm not seeing probe errors, so:
Tested-by: Lukas Wunner <lukas@wunner.de>
> @@ -67,8 +77,8 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
> __pcie_print_link_status(dev, false);
> up_read(&pci_bus_sem);
>
> + pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status);
> pcie_update_link_speed(port->subordinate, link_status);
> - pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
> return IRQ_HANDLED;
> }
I'd suggest leaving the call to pcie_update_link_speed() in
pcie_bw_notification_irq() to avoid the duplicate read of the
Link Status register.
With that addressed,
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Thanks,
Lukas
next prev parent reply other threads:[~2019-03-19 19:25 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 [this message]
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.
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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