releases/4.9.170/irqchip-mbigen-don-t-clear-eventid-when-freeing-an-m.patch

   1 From 8458b480cd451b18f9c59042d804721b506cb9d7 Mon Sep 17 00:00:00 2001
   2 From: Jianguo Chen <chenjianguo3@huawei.com>
   3 Date: Wed, 20 Mar 2019 18:54:21 +0000
   4 Subject: irqchip/mbigen: Don't clear eventid when freeing an MSI
   5
   6 [ Upstream commit fca269f201a8d9985c0a31fb60b15d4eb57cef80 ]
   7
   8 mbigen_write_msg clears eventid bits of a mbigen register
   9 when free a interrupt, because msi_domain_deactivate memset
  10 struct msg to zero. Then multiple mbigen pins with zero eventid
  11 will report the same interrupt number.
  12
  13 The eventid clear call trace:
  14                 free_irq
  15                 __free_irq
  16                 irq_shutdown
  17                 irq_domain_deactivate_irq
  18                 __irq_domain_deactivate_irq
  19                 __irq_domain_deactivate_irq
  20                 msi_domain_deactivate
  21                 platform_msi_write_msg
  22                 mbigen_write_msg
  23
  24 Signed-off-by: Jianguo Chen <chenjianguo3@huawei.com>
  25 [maz: massaged subject]
  26 Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
  27 Signed-off-by: Sasha Levin <sashal@kernel.org>
  28 ---
  29  drivers/irqchip/irq-mbigen.c | 3 +++
  30  1 file changed, 3 insertions(+)
  31
  32 diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
  33 index 05d87f60d929..406bfe618448 100644
  34 --- a/drivers/irqchip/irq-mbigen.c
  35 +++ b/drivers/irqchip/irq-mbigen.c
  36 @@ -160,6 +160,9 @@ static void mbigen_write_msg(struct msi_desc *desc, struct msi_msg *msg)
  37         void __iomem *base = d->chip_data;
  38         u32 val;
  39
  40 +       if (!msg->address_lo && !msg->address_hi)
  41 +               return;
  42 +
  43         base += get_mbigen_vec_reg(d->hwirq);
  44         val = readl_relaxed(base);
  45
  46 --
  47 2.19.1
  48