| Joel Stanley | 2b0f7b4 | 2016-07-19 23:26:28 +0930 | [diff] [blame^] | 1 | From e51e878aac1ea5018c7accac28afa4db8c620489 Mon Sep 17 00:00:00 2001 |
| 2 | From: Samuel Mendoza-Jonas <sam@mendozajonas.com> |
| 3 | Date: Wed, 13 Jul 2016 11:15:41 +1000 |
| 4 | Subject: [PATCH 09/10] tty/hvc: Use IRQF_SHARED for OPAL hvc consoles |
| 5 | |
| 6 | Commit 2def86a7200c |
| 7 | ("hvc: Convert to using interrupts instead of opal events") |
| 8 | enabled the use of interrupts in the hvc_driver for OPAL platforms. |
| 9 | However on machines with more than one hvc console, any console after |
| 10 | the first will fail to register an interrupt handler in |
| 11 | notifier_add_irq() since all consoles share the same IRQ number but do |
| 12 | not set the IRQF_SHARED flag: |
| 13 | |
| 14 | [ 51.179907] genirq: Flags mismatch irq 31. 00000000 (hvc_console) vs. |
| 15 | 00000000 (hvc_console) |
| 16 | [ 51.180010] hvc_open: request_irq failed with rc -16. |
| 17 | |
| 18 | This error propagates up to hvc_open() and the console is closed, but |
| 19 | OPAL will still generate interrupts that are not handled, leading to |
| 20 | rcu_sched stall warnings. |
| 21 | |
| 22 | Set IRQF_SHARED when calling request_irq, allowing additional consoles |
| 23 | to start properly. This is only set for consoles handled by |
| 24 | hvc_opal_probe(), leaving other types unaffected. |
| 25 | |
| 26 | Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com> |
| 27 | Cc: <stable@vger.kernel.org> # 4.1.x- |
| 28 | Signed-off-by: Joel Stanley <joel@jms.id.au> |
| 29 | --- |
| 30 | drivers/tty/hvc/hvc_console.h | 1 + |
| 31 | drivers/tty/hvc/hvc_irq.c | 7 +++++-- |
| 32 | drivers/tty/hvc/hvc_opal.c | 3 +++ |
| 33 | 3 files changed, 9 insertions(+), 2 deletions(-) |
| 34 | |
| 35 | diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h |
| 36 | index 913101980827..798c48d0d32c 100644 |
| 37 | --- a/drivers/tty/hvc/hvc_console.h |
| 38 | +++ b/drivers/tty/hvc/hvc_console.h |
| 39 | @@ -60,6 +60,7 @@ struct hvc_struct { |
| 40 | struct winsize ws; |
| 41 | struct work_struct tty_resize; |
| 42 | struct list_head next; |
| 43 | + unsigned long flags; |
| 44 | }; |
| 45 | |
| 46 | /* implemented by a low level driver */ |
| 47 | diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c |
| 48 | index c9adb0559f61..57d9df7ee1c9 100644 |
| 49 | --- a/drivers/tty/hvc/hvc_irq.c |
| 50 | +++ b/drivers/tty/hvc/hvc_irq.c |
| 51 | @@ -14,6 +14,9 @@ static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance) |
| 52 | /* if hvc_poll request a repoll, then kick the hvcd thread */ |
| 53 | if (hvc_poll(dev_instance)) |
| 54 | hvc_kick(); |
| 55 | + /* We're safe to always return IRQ_HANDLED as the hvcd thread will |
| 56 | + * iterate through each hvc_struct |
| 57 | + */ |
| 58 | return IRQ_HANDLED; |
| 59 | } |
| 60 | |
| 61 | @@ -28,8 +31,8 @@ int notifier_add_irq(struct hvc_struct *hp, int irq) |
| 62 | hp->irq_requested = 0; |
| 63 | return 0; |
| 64 | } |
| 65 | - rc = request_irq(irq, hvc_handle_interrupt, 0, |
| 66 | - "hvc_console", hp); |
| 67 | + rc = request_irq(irq, hvc_handle_interrupt, hp->flags, |
| 68 | + "hvc_console", hp); |
| 69 | if (!rc) |
| 70 | hp->irq_requested = 1; |
| 71 | return rc; |
| 72 | diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c |
| 73 | index 276b796b24e4..510799311099 100644 |
| 74 | --- a/drivers/tty/hvc/hvc_opal.c |
| 75 | +++ b/drivers/tty/hvc/hvc_opal.c |
| 76 | @@ -230,6 +230,9 @@ static int hvc_opal_probe(struct platform_device *dev) |
| 77 | hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS); |
| 78 | if (IS_ERR(hp)) |
| 79 | return PTR_ERR(hp); |
| 80 | + |
| 81 | + /* hvc consoles on powernv may need to share a single irq */ |
| 82 | + hp->flags = IRQF_SHARED; |
| 83 | dev_set_drvdata(&dev->dev, hp); |
| 84 | |
| 85 | return 0; |
| 86 | -- |
| 87 | 2.8.1 |
| 88 | |