linux-kernel - [PATCH 3/5] spi: bcm-qspi: Do not split transfers into small chunks

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Date:   Mon, 15 Jun 2020 16:05:55 +1200
From:   Mark Tomlinson <mark.tomlinson@...iedtelesis.co.nz>
To:     broonie@...nel.org, kdasu.kdev@...il.com
Cc:     linux-kernel@...r.kernel.org, linux-spi@...r.kernel.org,
        Mark Tomlinson <mark.tomlinson@...iedtelesis.co.nz>
Subject: [PATCH 3/5] spi: bcm-qspi: Do not split transfers into small chunks

Instead of splitting transfers into smaller parts, just perform the
operation that the higher level asked for.

Reviewed-by: Callum Sinclair <callum.sinclair@...iedtelesis.co.nz>
Reviewed-by: Chris Packham <chris.packham@...iedtelesis.co.nz>
Signed-off-by: Mark Tomlinson <mark.tomlinson@...iedtelesis.co.nz>
---
 drivers/spi/spi-bcm-qspi.c | 69 +++++++++++++++-----------------------
 1 file changed, 27 insertions(+), 42 deletions(-)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index 92e04d24359f..ce30ebf27f06 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -78,8 +78,6 @@
 #define BSPI_BPP_MODE_SELECT_MASK		BIT(8)
 #define BSPI_BPP_ADDR_SELECT_MASK		BIT(16)
 
-#define BSPI_READ_LENGTH			256
-
 /* MSPI register offsets */
 #define MSPI_SPCR0_LSB				0x000
 #define MSPI_SPCR0_MSB				0x004
@@ -888,9 +886,9 @@ static int bcm_qspi_bspi_exec_mem_op(struct spi_device *spi,
 				     const struct spi_mem_op *op)
 {
 	struct bcm_qspi *qspi = spi_master_get_devdata(spi->master);
-	u32 addr = 0, len, rdlen, len_words, from = 0;
+	u32 addr = 0, len, len_words, from = 0;
 	int ret = 0;
-	unsigned long timeo = msecs_to_jiffies(100);
+	unsigned long timeo = msecs_to_jiffies(1500);
 	struct bcm_qspi_soc_intc *soc_intc = qspi->soc_intc;
 
 	if (bcm_qspi_bspi_ver_three(qspi))
@@ -925,47 +923,34 @@ static int bcm_qspi_bspi_exec_mem_op(struct spi_device *spi,
 	 * into RAF buffer read lengths
 	 */
 	len = op->data.nbytes;
+	reinit_completion(&qspi->bspi_done);
+	bcm_qspi_enable_bspi(qspi);
+	len_words = (len + 3) >> 2;
+	qspi->bspi_rf_op = op;
+	qspi->bspi_rf_op_status = 0;
 	qspi->bspi_rf_op_idx = 0;
+	qspi->bspi_rf_op_len = len;
+	dev_dbg(&qspi->pdev->dev, "bspi xfr addr 0x%x len 0x%x", addr, len);
 
-	do {
-		if (len > BSPI_READ_LENGTH)
-			rdlen = BSPI_READ_LENGTH;
-		else
-			rdlen = len;
-
-		reinit_completion(&qspi->bspi_done);
-		bcm_qspi_enable_bspi(qspi);
-		len_words = (rdlen + 3) >> 2;
-		qspi->bspi_rf_op = op;
-		qspi->bspi_rf_op_status = 0;
-		qspi->bspi_rf_op_len = rdlen;
-		dev_dbg(&qspi->pdev->dev,
-			"bspi xfr addr 0x%x len 0x%x", addr, rdlen);
-		bcm_qspi_write(qspi, BSPI, BSPI_RAF_START_ADDR, addr);
-		bcm_qspi_write(qspi, BSPI, BSPI_RAF_NUM_WORDS, len_words);
-		bcm_qspi_write(qspi, BSPI, BSPI_RAF_WATERMARK, 0);
-		if (qspi->soc_intc) {
-			/*
-			 * clear soc MSPI and BSPI interrupts and enable
-			 * BSPI interrupts.
-			 */
-			soc_intc->bcm_qspi_int_ack(soc_intc, MSPI_BSPI_DONE);
-			soc_intc->bcm_qspi_int_set(soc_intc, BSPI_DONE, true);
-		}
-
-		/* Must flush previous writes before starting BSPI operation */
-		mb();
-		bcm_qspi_bspi_lr_start(qspi);
-		if (!wait_for_completion_timeout(&qspi->bspi_done, timeo)) {
-			dev_err(&qspi->pdev->dev, "timeout waiting for BSPI\n");
-			ret = -ETIMEDOUT;
-			break;
-		}
+	bcm_qspi_write(qspi, BSPI, BSPI_RAF_START_ADDR, addr);
+	bcm_qspi_write(qspi, BSPI, BSPI_RAF_NUM_WORDS, len_words);
+	bcm_qspi_write(qspi, BSPI, BSPI_RAF_WATERMARK, 0);
+	if (qspi->soc_intc) {
+		/*
+		 * clear soc MSPI and BSPI interrupts and enable
+		 * BSPI interrupts.
+		 */
+		soc_intc->bcm_qspi_int_ack(soc_intc, MSPI_BSPI_DONE);
+		soc_intc->bcm_qspi_int_set(soc_intc, BSPI_DONE, true);
+	}
 
-		/* set msg return length */
-		addr += rdlen;
-		len -= rdlen;
-	} while (len);
+	/* Must flush previous writes before starting BSPI operation */
+	mb();
+	bcm_qspi_bspi_lr_start(qspi);
+	if (!wait_for_completion_timeout(&qspi->bspi_done, timeo)) {
+		dev_err(&qspi->pdev->dev, "timeout waiting for BSPI\n");
+		ret = -ETIMEDOUT;
+	}
 
 	return ret;
 }
-- 
2.27.0