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Diffstat (limited to 'target/linux/ipq806x/patches-3.18/003-spi-qup-Ensure-done-detection.patch')
-rw-r--r--target/linux/ipq806x/patches-3.18/003-spi-qup-Ensure-done-detection.patch56
1 files changed, 56 insertions, 0 deletions
diff --git a/target/linux/ipq806x/patches-3.18/003-spi-qup-Ensure-done-detection.patch b/target/linux/ipq806x/patches-3.18/003-spi-qup-Ensure-done-detection.patch
new file mode 100644
index 0000000..7052227
--- /dev/null
+++ b/target/linux/ipq806x/patches-3.18/003-spi-qup-Ensure-done-detection.patch
@@ -0,0 +1,56 @@
+From 4faba89e3ffbb1c5f6232651375b9b3212b50f02 Mon Sep 17 00:00:00 2001
+From: Andy Gross <agross@codeaurora.org>
+Date: Thu, 15 Jan 2015 17:56:02 -0800
+Subject: [PATCH] spi: qup: Ensure done detection
+
+This patch fixes an issue where a SPI transaction has completed, but the done
+condition is missed. This occurs because at the time of interrupt the
+MAX_INPUT_DONE_FLAG is not asserted. However, in the process of reading blocks
+of data from the FIFO, the last portion of data comes in.
+
+The opflags read at the beginning of the irq handler no longer matches the
+current opflag state. To get around this condition, the block read function
+should update the opflags so that done detection is correct after the return.
+
+Change-Id: If109e0eeb432f96000d765c4b34dbb2269f8093f
+Signed-off-by: Andy Gross <agross@codeaurora.org>
+---
+ drivers/spi/spi-qup.c | 12 +++++++-----
+ 1 file changed, 7 insertions(+), 5 deletions(-)
+
+--- a/drivers/spi/spi-qup.c
++++ b/drivers/spi/spi-qup.c
+@@ -298,7 +298,7 @@ static void spi_qup_fifo_write(struct sp
+ }
+
+ static void spi_qup_block_read(struct spi_qup *controller,
+- struct spi_transfer *xfer)
++ struct spi_transfer *xfer, u32 *opflags)
+ {
+ u32 data;
+ u32 reads_per_blk = controller->in_blk_sz >> 2;
+@@ -327,10 +327,12 @@ static void spi_qup_block_read(struct sp
+
+ /*
+ * Due to extra stickiness of the QUP_OP_IN_SERVICE_FLAG during block
+- * reads, it has to be cleared again at the very end
++ * reads, it has to be cleared again at the very end. However, be sure
++ * to refresh opflags value because MAX_INPUT_DONE_FLAG may now be
++ * present and this is used to determine if transaction is complete
+ */
+- if (readl_relaxed(controller->base + QUP_OPERATIONAL) &
+- QUP_OP_MAX_INPUT_DONE_FLAG)
++ *opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
++ if (*opflags & QUP_OP_MAX_INPUT_DONE_FLAG)
+ writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
+ controller->base + QUP_OPERATIONAL);
+
+@@ -633,7 +635,7 @@ static irqreturn_t spi_qup_qup_irq(int i
+ if (!controller->use_dma) {
+ if (opflags & QUP_OP_IN_SERVICE_FLAG) {
+ if (opflags & QUP_OP_IN_BLOCK_READ_REQ)
+- spi_qup_block_read(controller, xfer);
++ spi_qup_block_read(controller, xfer, &opflags);
+ else
+ spi_qup_fifo_read(controller, xfer);
+ }