Applied "spi: mediatek: Don't modify spi_transfer when transfer." to the spi tree

Commit Message

Mark Brown Sept. 18, 2018, 4:38 p.m. UTC

The patch

   spi: mediatek: Don't modify spi_transfer when transfer.

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 00bca73bfca4fb0ab089b94cad0fc83d8b49c25f Mon Sep 17 00:00:00 2001
From: Peter Shih <[e-mail]>
Date: Mon, 10 Sep 2018 11:54:21 +0800
Subject: [PATCH] spi: mediatek: Don't modify spi_transfer when transfer.

Mediatek SPI driver modifies some fields (tx_buf, rx_buf, len, tx_dma,
rx_dma) of the spi_transfer* passed in when doing transfer_one and in
interrupt handler. This is somewhat unexpected, and there are some
caller (e.g. Cr50 spi driver) that reuse the spi_transfer for multiple
messages. Add a field to record how many bytes have been transferred,
and calculate the right len / buffer based on it instead.

Signed-off-by: Pi-Hsun Shih <[e-mail]>

Change-Id: I23e218cd964f16c0b2b26127d4a5ca6529867673
Signed-off-by: Mark Brown <[e-mail]>
---
 drivers/spi/spi-mt65xx.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

Patch

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 86bf45667a04..3dc31627c655 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -98,6 +98,7 @@  struct mtk_spi {
 	struct clk *parent_clk, *sel_clk, *spi_clk;
 	struct spi_transfer *cur_transfer;
 	u32 xfer_len;
+	u32 num_xfered;
 	struct scatterlist *tx_sgl, *rx_sgl;
 	u32 tx_sgl_len, rx_sgl_len;
 	const struct mtk_spi_compatible *dev_comp;
@@ -385,6 +386,7 @@  static int mtk_spi_fifo_transfer(struct spi_master *master,
 
 	mdata->cur_transfer = xfer;
 	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
+	mdata->num_xfered = 0;
 	mtk_spi_prepare_transfer(master, xfer);
 	mtk_spi_setup_packet(master);
 
@@ -415,6 +417,7 @@  static int mtk_spi_dma_transfer(struct spi_master *master,
 	mdata->tx_sgl_len = 0;
 	mdata->rx_sgl_len = 0;
 	mdata->cur_transfer = xfer;
+	mdata->num_xfered = 0;
 
 	mtk_spi_prepare_transfer(master, xfer);
 
@@ -482,7 +485,7 @@  static int mtk_spi_setup(struct spi_device *spi)
 
 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
 {
-	u32 cmd, reg_val, cnt, remainder;
+	u32 cmd, reg_val, cnt, remainder, len;
 	struct spi_master *master = dev_id;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 	struct spi_transfer *trans = mdata->cur_transfer;
@@ -497,36 +500,38 @@  static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
 		if (trans->rx_buf) {
 			cnt = mdata->xfer_len / 4;
 			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
-				     trans->rx_buf, cnt);
+				     trans->rx_buf + mdata->num_xfered, cnt);
 			remainder = mdata->xfer_len % 4;
 			if (remainder > 0) {
 				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
-				memcpy(trans->rx_buf + (cnt * 4),
-					&reg_val, remainder);
+				memcpy(trans->rx_buf +
+					mdata->num_xfered +
+					(cnt * 4),
+					&reg_val,
+					remainder);
 			}
 		}
 
-		trans->len -= mdata->xfer_len;
-		if (!trans->len) {
+		mdata->num_xfered += mdata->xfer_len;
+		if (mdata->num_xfered == trans->len) {
 			spi_finalize_current_transfer(master);
 			return IRQ_HANDLED;
 		}
 
-		if (trans->tx_buf)
-			trans->tx_buf += mdata->xfer_len;
-		if (trans->rx_buf)
-			trans->rx_buf += mdata->xfer_len;
-
-		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, trans->len);
+		len = trans->len - mdata->num_xfered;
+		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, len);
 		mtk_spi_setup_packet(master);
 
-		cnt = trans->len / 4;
-		iowrite32_rep(mdata->base + SPI_TX_DATA_REG, trans->tx_buf, cnt);
+		cnt = len / 4;
+		iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
+				trans->tx_buf + mdata->num_xfered, cnt);
 
-		remainder = trans->len % 4;
+		remainder = len % 4;
 		if (remainder > 0) {
 			reg_val = 0;
-			memcpy(&reg_val, trans->tx_buf + (cnt * 4), remainder);
+			memcpy(&reg_val,
+				trans->tx_buf + (cnt * 4) + mdata->num_xfered,
+				remainder);
 			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
 		}