diff options
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.patch | 56 |
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); + } |