Patch "spi: mediatek: Fix package division error" has been added to the 6.0-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    spi: mediatek: Fix package division error

to the 6.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     spi-mediatek-fix-package-division-error.patch
and it can be found in the queue-6.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0c4a41322e225c3241634c57b425a178fe078cab
Author: zhichao.liu <zhichao.liu@xxxxxxxxxxxx>
Date:   Fri Oct 21 17:16:53 2022 +0800

    spi: mediatek: Fix package division error
    
    [ Upstream commit cf82d0ecb84e8ef9958721193f901609b408655b ]
    
    Commit 7e963fb2a33ce ("spi: mediatek: add ipm design support
    for MT7986") makes a mistake on package dividing operation
    (one change is missing), need to fix it.
    
    Background:
    Ipm design is expanding the HW capability of dma (adjust package
    length from 1KB to 64KB), and using "dev_comp->ipm_support" flag
    to indicate it.
    
    Issue description:
    Ipm support patch (said above) is missing to handle remainder at
    package dividing operation.
    One case, a transmission length is 65KB, is will divide to 1K
    (package length) * 65(package loop) in non-ipm desgin case, and
    will divide to 64K(package length) * 1(package loop) + 1K(remainder)
    in ipm design case. And the 1K remainder will be lost with the
    current SW flow, and the transmission will be failure.
    So, it should be fixed.
    
    Solution:
    Add "ipm_design" flag in function "mtk_spi_get_mult_delta()" to
    indicate HW capability, and modify the parameters corespondingly.
    
    fixes: 7e963fb2a33ce ("spi: mediatek: add ipm design support for MT7986")
    Signed-off-by: zhichao.liu <zhichao.liu@xxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20221021091653.18297-1-zhichao.liu@xxxxxxxxxxxx
    Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 0a3b9f7eed30..cd9dc358d396 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -551,14 +551,17 @@ static void mtk_spi_enable_transfer(struct spi_master *master)
 	writel(cmd, mdata->base + SPI_CMD_REG);
 }
 
-static int mtk_spi_get_mult_delta(u32 xfer_len)
+static int mtk_spi_get_mult_delta(struct mtk_spi *mdata, u32 xfer_len)
 {
-	u32 mult_delta;
+	u32 mult_delta = 0;
 
-	if (xfer_len > MTK_SPI_PACKET_SIZE)
-		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
-	else
-		mult_delta = 0;
+	if (mdata->dev_comp->ipm_design) {
+		if (xfer_len > MTK_SPI_IPM_PACKET_SIZE)
+			mult_delta = xfer_len % MTK_SPI_IPM_PACKET_SIZE;
+	} else {
+		if (xfer_len > MTK_SPI_PACKET_SIZE)
+			mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
+	}
 
 	return mult_delta;
 }
@@ -570,22 +573,22 @@ static void mtk_spi_update_mdata_len(struct spi_master *master)
 
 	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
 		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
-			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
+			mult_delta = mtk_spi_get_mult_delta(mdata, mdata->rx_sgl_len);
 			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
 			mdata->rx_sgl_len = mult_delta;
 			mdata->tx_sgl_len -= mdata->xfer_len;
 		} else {
-			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
+			mult_delta = mtk_spi_get_mult_delta(mdata, mdata->tx_sgl_len);
 			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
 			mdata->tx_sgl_len = mult_delta;
 			mdata->rx_sgl_len -= mdata->xfer_len;
 		}
 	} else if (mdata->tx_sgl_len) {
-		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
+		mult_delta = mtk_spi_get_mult_delta(mdata, mdata->tx_sgl_len);
 		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
 		mdata->tx_sgl_len = mult_delta;
 	} else if (mdata->rx_sgl_len) {
-		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
+		mult_delta = mtk_spi_get_mult_delta(mdata, mdata->rx_sgl_len);
 		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
 		mdata->rx_sgl_len = mult_delta;
 	}