target/linux/ipq806x/patches-4.9/0007-spi-qup-properly-detect-extra-interrupts.patch

   1 From 0f32f976ebaa7d8643fcd9419f12bc801ba14407 Mon Sep 17 00:00:00 2001
   2 From: Matthew McClintock <mmcclint@codeaurora.org>
   3 Date: Thu, 10 Mar 2016 16:44:55 -0600
   4 Subject: [PATCH 07/69] spi: qup: properly detect extra interrupts
   5
   6 It's possible for a SPI transaction to complete and get another
   7 interrupt and have it processed on the same spi_transfer before the
   8 transfer_one can set it to NULL.
   9
  10 This masks unexpected interrupts, so let's set the spi_transfer to
  11 NULL in the interrupt once the transaction is done. So we can
  12 properly detect these bad interrupts and print warning messages.
  13
  14 Signed-off-by: Matthew McClintock <mmcclint@codeaurora.org>
  15 ---
  16  drivers/spi/spi-qup.c | 15 +++++++++------
  17  1 file changed, 9 insertions(+), 6 deletions(-)
  18
  19 diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
  20 index 10c7eb139c9e..d0cbb37d53b0 100644
  21 --- a/drivers/spi/spi-qup.c
  22 +++ b/drivers/spi/spi-qup.c
  23 @@ -507,6 +507,7 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
  24         u32 opflags, qup_err, spi_err;
  25         unsigned long flags;
  26         int error = 0;
  27 +       bool done = 0;
  28
  29         spin_lock_irqsave(&controller->lock, flags);
  30         xfer = controller->xfer;
  31 @@ -565,16 +566,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
  32                         spi_qup_write(controller, xfer);
  33         }
  34
  35 -       spin_lock_irqsave(&controller->lock, flags);
  36 -       controller->error = error;
  37 -       controller->xfer = xfer;
  38 -       spin_unlock_irqrestore(&controller->lock, flags);
  39 -
  40         /* re-read opflags as flags may have changed due to actions above */
  41         opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
  42
  43         if ((controller->rx_bytes == xfer->len &&
  44                 (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
  45 +               done = true;
  46 +
  47 +       spin_lock_irqsave(&controller->lock, flags);
  48 +       controller->error = error;
  49 +       controller->xfer = done ? NULL : xfer;
  50 +       spin_unlock_irqrestore(&controller->lock, flags);
  51 +
  52 +       if (done)
  53                 complete(&controller->done);
  54
  55         return IRQ_HANDLED;
  56 @@ -767,7 +771,6 @@ static int spi_qup_transfer_one(struct spi_master *master,
  57  exit:
  58         spi_qup_set_state(controller, QUP_STATE_RESET);
  59         spin_lock_irqsave(&controller->lock, flags);
  60 -       controller->xfer = NULL;
  61         if (!ret)
  62                 ret = controller->error;
  63         spin_unlock_irqrestore(&controller->lock, flags);
  64 --
  65 2.11.0
  66