target/linux/oxnas/patches-5.4/001-irqchip-versatile-fpga-Handle-chained-IRQs-properly.patch

   1 From patchwork Thu Mar 19 02:34:48 2020
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   5 X-Patchwork-Submitter: Sungbo Eo <mans0n@gorani.run>
   6 X-Patchwork-Id: 11446405
   7 From: Sungbo Eo <mans0n@gorani.run>
   8 To: Linus Walleij <linus.walleij@linaro.org>,
   9  Thomas Gleixner <tglx@linutronix.de>, Jason Cooper <jason@lakedaemon.net>,
  10  Marc Zyngier <maz@kernel.org>, linux-arm-kernel@lists.infradead.org,
  11  linux-kernel@vger.kernel.org, linux-oxnas@groups.io
  12 Subject: [PATCH v2] irqchip/versatile-fpga: Handle chained IRQs properly
  13 Date: Thu, 19 Mar 2020 11:34:48 +0900
  14 Message-Id: <20200319023448.1479701-1-mans0n@gorani.run>
  15 In-Reply-To: <002b72cab9896fa5ac76a52e0cb503ff@kernel.org>
  16 References: <002b72cab9896fa5ac76a52e0cb503ff@kernel.org>
  17 MIME-Version: 1.0
  18 List-Id: <linux-arm-kernel.lists.infradead.org>
  19 Cc: Sungbo Eo <mans0n@gorani.run>, Neil Armstrong <narmstrong@baylibre.com>
  20 Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org>
  21
  22 Enclose the chained handler with chained_irq_{enter,exit}(), so that the
  23 muxed interrupts get properly acked.
  24
  25 This patch also fixes a reboot bug on OX820 SoC, where the jiffies timer
  26 interrupt is never acked. The kernel waits a clock tick forever in
  27 calibrate_delay_converge(), which leads to a boot hang.
  28
  29 Fixes: c41b16f8c9d9 ("ARM: integrator/versatile: consolidate FPGA IRQ handling code")
  30 Signed-off-by: Sungbo Eo <mans0n@gorani.run>
  31 Cc: Neil Armstrong <narmstrong@baylibre.com>
  32 ---
  33 v2: moved readl below chained_irq_enter()
  34     added Fixes tag
  35
  36  drivers/irqchip/irq-versatile-fpga.c | 12 ++++++++++--
  37  1 file changed, 10 insertions(+), 2 deletions(-)
  38
  39 --- a/drivers/irqchip/irq-versatile-fpga.c
  40 +++ b/drivers/irqchip/irq-versatile-fpga.c
  41 @@ -6,6 +6,7 @@
  42  #include <linux/irq.h>
  43  #include <linux/io.h>
  44  #include <linux/irqchip.h>
  45 +#include <linux/irqchip/chained_irq.h>
  46  #include <linux/irqchip/versatile-fpga.h>
  47  #include <linux/irqdomain.h>
  48  #include <linux/module.h>
  49 @@ -68,12 +69,16 @@ static void fpga_irq_unmask(struct irq_d
  50
  51  static void fpga_irq_handle(struct irq_desc *desc)
  52  {
  53 +       struct irq_chip *chip = irq_desc_get_chip(desc);
  54         struct fpga_irq_data *f = irq_desc_get_handler_data(desc);
  55 -       u32 status = readl(f->base + IRQ_STATUS);
  56 +       u32 status;
  57
  58 +       chained_irq_enter(chip, desc);
  59 +
  60 +       status = readl(f->base + IRQ_STATUS);
  61         if (status == 0) {
  62                 do_bad_IRQ(desc);
  63 -               return;
  64 +               goto out;
  65         }
  66
  67         do {
  68 @@ -82,6 +87,9 @@ static void fpga_irq_handle(struct irq_d
  69                 status &= ~(1 << irq);
  70                 generic_handle_irq(irq_find_mapping(f->domain, irq));
  71         } while (status);
  72 +
  73 +out:
  74 +       chained_irq_exit(chip, desc);
  75  }
  76
  77  /*