• Sam Mendoza-Jonas's avatar
    tty/hvc: Use IRQF_SHARED for OPAL hvc consoles · bbc3dfe8
    Sam Mendoza-Jonas authored
    Commit 2def86a7 ("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: 's avatarSamuel Mendoza-Jonas <sam@mendozajonas.com>
    Signed-off-by: 's avatarMichael Ellerman <mpe@ellerman.id.au>
    bbc3dfe8