target/linux/generic/pending-4.19/343-MIPS-ath79-Fix-potentially-missed-IRQ-handling-durin.patch

   1 From 3fe7841bf5a582dc7fd198e5bf70162ea418a22a Mon Sep 17 00:00:00 2001
   2 From: Koen Vandeputte <koen.vandeputte@ncentric.com>
   3 Date: Wed, 11 Sep 2019 11:02:19 +0200
   4 Subject: [PATCH] MIPS: ath79: Fix potentially missed IRQ handling during
   5  dispatch
   6
   7 If both interrupts are set in the current implementation
   8 only the 1st will be handled and the 2nd will be skipped
   9 due to the "if else" condition.
  10
  11 Fix this by using the same approach as done for QCA955x
  12 just below it.
  13
  14 Fixes: fce5cc6e0ddc ("MIPS: ath79: add IRQ handling code for AR934X")
  15 Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
  16 CC: Felix Fietkau <nbd@nbd.name>
  17 CC: Gabor Juhos <juhosg@freemail.hu>
  18 CC: James Hogan <jhogan@kernel.org>
  19 CC: Paul Burton <paul.burton@mips.com>
  20 CC: Ralf Baechle <ralf@linux-mips.org>
  21 CC: stable@vger.kernel.org # v3.2+
  22 ---
  23  arch/mips/ath79/irq.c | 12 +++++++++---
  24  1 file changed, 9 insertions(+), 3 deletions(-)
  25
  26 diff --git a/arch/mips/ath79/irq.c b/arch/mips/ath79/irq.c
  27 index 2dfff1f19004..a03a6bcaf6fd 100644
  28 --- a/arch/mips/ath79/irq.c
  29 +++ b/arch/mips/ath79/irq.c
  30 @@ -32,15 +32,21 @@ static void ar934x_ip2_irq_dispatch(struct irq_desc *desc)
  31         u32 status;
  32
  33         status = ath79_reset_rr(AR934X_RESET_REG_PCIE_WMAC_INT_STATUS);
  34 +       status &= AR934X_PCIE_WMAC_INT_PCIE_ALL | AR934X_PCIE_WMAC_INT_WMAC_ALL;
  35 +
  36 +       if (status == 0) {
  37 +               spurious_interrupt();
  38 +               return;
  39 +       }
  40
  41         if (status & AR934X_PCIE_WMAC_INT_PCIE_ALL) {
  42                 ath79_ddr_wb_flush(3);
  43                 generic_handle_irq(ATH79_IP2_IRQ(0));
  44 -       } else if (status & AR934X_PCIE_WMAC_INT_WMAC_ALL) {
  45 +       }
  46 +
  47 +       if (status & AR934X_PCIE_WMAC_INT_WMAC_ALL) {
  48                 ath79_ddr_wb_flush(4);
  49                 generic_handle_irq(ATH79_IP2_IRQ(1));
  50 -       } else {
  51 -               spurious_interrupt();
  52         }
  53  }
  54
  55 --
  56 2.17.1
  57