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 --- a/drivers/spi/spi-qup.c
  20 +++ b/drivers/spi/spi-qup.c
  21 @@ -507,6 +507,7 @@ static irqreturn_t spi_qup_qup_irq(int i
  22         u32 opflags, qup_err, spi_err;
  23         unsigned long flags;
  24         int error = 0;
  25 +       bool done = 0;
  26
  27         spin_lock_irqsave(&controller->lock, flags);
  28         xfer = controller->xfer;
  29 @@ -565,16 +566,19 @@ static irqreturn_t spi_qup_qup_irq(int i
  30                         spi_qup_write(controller, xfer);
  31         }
  32
  33 -       spin_lock_irqsave(&controller->lock, flags);
  34 -       controller->error = error;
  35 -       controller->xfer = xfer;
  36 -       spin_unlock_irqrestore(&controller->lock, flags);
  37 -
  38         /* re-read opflags as flags may have changed due to actions above */
  39         opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
  40
  41         if ((controller->rx_bytes == xfer->len &&
  42                 (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
  43 +               done = true;
  44 +
  45 +       spin_lock_irqsave(&controller->lock, flags);
  46 +       controller->error = error;
  47 +       controller->xfer = done ? NULL : xfer;
  48 +       spin_unlock_irqrestore(&controller->lock, flags);
  49 +
  50 +       if (done)
  51                 complete(&controller->done);
  52
  53         return IRQ_HANDLED;
  54 @@ -767,7 +771,6 @@ static int spi_qup_transfer_one(struct s
  55  exit:
  56         spi_qup_set_state(controller, QUP_STATE_RESET);
  57         spin_lock_irqsave(&controller->lock, flags);
  58 -       controller->xfer = NULL;
  59         if (!ret)
  60                 ret = controller->error;
  61         spin_unlock_irqrestore(&controller->lock, flags);