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