[PATCH] spi: mediatek: Fix package division error

[PATCH] spi: mediatek: Fix package division error

[Zhichao Liu]

From: "zhichao.liu" <zhichao.liu@mediatek.com>

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@mediatek.com>
---
 drivers/spi/spi-mt65xx.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 11aeae7fe7fc..a33c9a3de395 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;
 	}
-- 
2.18.0


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Re: [PATCH] spi: mediatek: Fix package division error

[Mark Brown]

On Fri, 21 Oct 2022 17:16:53 +0800, Zhichao Liu wrote:
> From: "zhichao.liu" <zhichao.liu@mediatek.com>
> 
> 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.
> 
> [...]

Applied to

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

Thanks!

[1/1] spi: mediatek: Fix package division error
      commit: cf82d0ecb84e8ef9958721193f901609b408655b

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

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