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-rw-r--r--target/linux/ipq806x/patches-4.4/714-spi-qup-properly-detect-extra-interrupts.patch67
1 files changed, 67 insertions, 0 deletions
diff --git a/target/linux/ipq806x/patches-4.4/714-spi-qup-properly-detect-extra-interrupts.patch b/target/linux/ipq806x/patches-4.4/714-spi-qup-properly-detect-extra-interrupts.patch
new file mode 100644
index 0000000000..d8a9b31462
--- /dev/null
+++ b/target/linux/ipq806x/patches-4.4/714-spi-qup-properly-detect-extra-interrupts.patch
@@ -0,0 +1,67 @@
+From b69e5e855aaae2dd9f7fc6f4a40af8e6e0cf98ee Mon Sep 17 00:00:00 2001
+From: Matthew McClintock <mmcclint@codeaurora.org>
+Date: Thu, 10 Mar 2016 16:44:55 -0600
+Subject: [PATCH] spi: qup: properly detect extra interrupts
+
+It's possible for a SPI transaction to complete and get another
+interrupt and have it processed on the same spi_transfer before the
+transfer_one can set it to NULL.
+
+This masks unexpected interrupts, so let's set the spi_transfer to
+NULL in the interrupt once the transaction is done. So we can
+properly detect these bad interrupts and print warning messages.
+
+Change-Id: I0e70ed59fb50e5c48a72a38f74bd178b17c9f24d
+Signed-off-by: Matthew McClintock <mmcclint@codeaurora.org>
+---
+ drivers/spi/spi-qup.c | 15 +++++++++------
+ 1 file changed, 9 insertions(+), 6 deletions(-)
+
+diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
+index e487416..45e30c7 100644
+--- a/drivers/spi/spi-qup.c
++++ b/drivers/spi/spi-qup.c
+@@ -509,6 +509,7 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
+ u32 opflags, qup_err, spi_err;
+ unsigned long flags;
+ int error = 0;
++ bool done = 0;
+
+ spin_lock_irqsave(&controller->lock, flags);
+ xfer = controller->xfer;
+@@ -567,16 +568,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
+ spi_qup_write(controller, xfer);
+ }
+
+- spin_lock_irqsave(&controller->lock, flags);
+- controller->error = error;
+- controller->xfer = xfer;
+- spin_unlock_irqrestore(&controller->lock, flags);
+-
+ /* re-read opflags as flags may have changed due to actions above */
+ opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
+
+ if ((controller->rx_bytes == xfer->len &&
+ (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) || error)
++ done = true;
++
++ spin_lock_irqsave(&controller->lock, flags);
++ controller->error = error;
++ controller->xfer = done ? NULL : xfer;
++ spin_unlock_irqrestore(&controller->lock, flags);
++
++ if (done)
+ complete(&controller->done);
+
+ return IRQ_HANDLED;
+@@ -769,7 +773,6 @@ static int spi_qup_transfer_one(struct spi_master *master,
+ exit:
+ spi_qup_set_state(controller, QUP_STATE_RESET);
+ spin_lock_irqsave(&controller->lock, flags);
+- controller->xfer = NULL;
+ if (!ret)
+ ret = controller->error;
+ spin_unlock_irqrestore(&controller->lock, flags);
+--
+2.7.2
+