[PATCH] i2c: mediatek: move dma reset before i2c reset

[PATCH] i2c: mediatek: move dma reset before i2c reset

[qii.wang]

From: Qii Wang <qii.wang@mediatek.com>

The i2c driver default do dma reset after i2c reset, but sometimes
i2c reset will trigger dma tx2rx, then apdma write data to dram
which has been i2c_put_dma_safe_msg_buf(kfree). Move dma reset
before i2c reset in mtk_i2c_init_hw to fix it.

Signed-off-by: Qii Wang <qii.wang@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 0cbdfbe..33de99b 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -475,6 +475,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 {
 	u16 control_reg;
 
+	writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
+	udelay(50);
+	writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
+
 	mtk_i2c_writew(i2c, I2C_SOFT_RST, OFFSET_SOFTRESET);
 
 	/* Set ioconfig */
@@ -529,10 +533,6 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 
 	mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL);
 	mtk_i2c_writew(i2c, I2C_DELAY_LEN, OFFSET_DELAY_LEN);
-
-	writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
-	udelay(50);
-	writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
 }
 
 static const struct i2c_spec_values *mtk_i2c_get_spec(unsigned int speed)
-- 
1.9.1
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Re: [PATCH] i2c: mediatek: move dma reset before i2c reset

[Wolfram Sang]

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On Fri, Oct 30, 2020 at 07:58:01PM +0800, qii.wang@mediatek.com wrote:
> From: Qii Wang <qii.wang@mediatek.com>
> 
> The i2c driver default do dma reset after i2c reset, but sometimes
> i2c reset will trigger dma tx2rx, then apdma write data to dram
> which has been i2c_put_dma_safe_msg_buf(kfree). Move dma reset
> before i2c reset in mtk_i2c_init_hw to fix it.
> 
> Signed-off-by: Qii Wang <qii.wang@mediatek.com>

Applied to for-current, thanks!


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