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| author | Sam Mendoza-Jonas <sam@mendozajonas.com> | 2016-07-11 05:38:57 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-07-27 04:38:18 +0200 |
| commit | bbc3dfe8805de86874b1a1b1429a002e8670043e (patch) | |
| tree | 5fc55f25dd0daf89975481a3320fb7c24c9f0ecd /drivers/tty/hvc | |
| parent | selftests/powerpc: exec() with suspended transaction (diff) | |
| download | linux-bbc3dfe8805de86874b1a1b1429a002e8670043e.tar.xz linux-bbc3dfe8805de86874b1a1b1429a002e8670043e.zip | |
tty/hvc: Use IRQF_SHARED for OPAL hvc consoles
Commit 2def86a7200c ("hvc: Convert to using interrupts instead of opal
events") enabled the use of interrupts in the hvc_driver for OPAL
platforms. However on machines with more than one hvc console, any
console after the first will fail to register an interrupt handler in
notifier_add_irq() since all consoles share the same IRQ number but do
not set the IRQF_SHARED flag:
genirq: Flags mismatch irq 31. 00000000 (hvc_console) vs. 00000000 (hvc_console)
hvc_open: request_irq failed with rc -16.
This error propagates up to hvc_open() and the console is closed, but
OPAL will still generate interrupts that are not handled, leading to
rcu_sched stall warnings.
Set IRQF_SHARED when calling request_irq(), allowing additional consoles
to start properly. This is only set for consoles handled by
hvc_opal_probe(), leaving other types unaffected.
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/tty/hvc')
| -rw-r--r-- | drivers/tty/hvc/hvc_console.h | 1 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_irq.c | 9 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_opal.c | 3 |
3 files changed, 11 insertions, 2 deletions
diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h index 913101980827..798c48d0d32c 100644 --- a/drivers/tty/hvc/hvc_console.h +++ b/drivers/tty/hvc/hvc_console.h @@ -60,6 +60,7 @@ struct hvc_struct { struct winsize ws; struct work_struct tty_resize; struct list_head next; + unsigned long flags; }; /* implemented by a low level driver */ diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c index c9adb0559f61..bc7a96874637 100644 --- a/drivers/tty/hvc/hvc_irq.c +++ b/drivers/tty/hvc/hvc_irq.c @@ -14,6 +14,11 @@ static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance) /* if hvc_poll request a repoll, then kick the hvcd thread */ if (hvc_poll(dev_instance)) hvc_kick(); + + /* + * We're safe to always return IRQ_HANDLED as the hvcd thread will + * iterate through each hvc_struct. + */ return IRQ_HANDLED; } @@ -28,8 +33,8 @@ int notifier_add_irq(struct hvc_struct *hp, int irq) hp->irq_requested = 0; return 0; } - rc = request_irq(irq, hvc_handle_interrupt, 0, - "hvc_console", hp); + rc = request_irq(irq, hvc_handle_interrupt, hp->flags, + "hvc_console", hp); if (!rc) hp->irq_requested = 1; return rc; diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c index 47b54c6aefd2..b7cd0ae7d927 100644 --- a/drivers/tty/hvc/hvc_opal.c +++ b/drivers/tty/hvc/hvc_opal.c @@ -224,6 +224,9 @@ static int hvc_opal_probe(struct platform_device *dev) hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS); if (IS_ERR(hp)) return PTR_ERR(hp); + + /* hvc consoles on powernv may need to share a single irq */ + hp->flags = IRQF_SHARED; dev_set_drvdata(&dev->dev, hp); return 0; |