From: Carlos Song <carlos.song@xxxxxxx>
Return -EPROBE_DEFER when dma_request_slave_channel() because DMA driver
have not ready yet.
Move i2c_imx_dma_request() before registering I2C adapter to avoid
infinite loop of .probe() calls to the same driver, see "e8c220fac415
Revert "i2c: imx: improve the error handling in i2c_imx_dma_request()""
and "Documentation/driver-api/driver-model/driver.rst".
Use CPU mode to avoid stuck registering i2c adapter when DMA resources
are unavailable.
Signed-off-by: Carlos Song <carlos.song@xxxxxxx>
Signed-off-by: Clark Wang <xiaoning.wang@xxxxxxx>
---
Change for V2:
- According to Frank's comments, wrap at 75 char and Simplify fix code
at i2c_imx_dma_request().
- Use strict patch check, fix alignment warning at i2c_imx_dma_request()
---
drivers/i2c/busses/i2c-imx.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 5ed4cb61e262..4e5633166a1e 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -397,17 +397,16 @@ static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx)
}
/* Functions for DMA support */
-static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
- dma_addr_t phy_addr)
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, dma_addr_t phy_addr)
{
struct imx_i2c_dma *dma;
struct dma_slave_config dma_sconfig;
- struct device *dev = &i2c_imx->adapter.dev;
+ struct device *dev = i2c_imx->adapter.dev.parent;
int ret;
dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
if (!dma)
- return;
+ return -ENOMEM;
dma->chan_tx = dma_request_chan(dev, "tx");
if (IS_ERR(dma->chan_tx)) {
@@ -452,7 +451,7 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
- return;
+ return 0;
fail_rx:
dma_release_channel(dma->chan_rx);
@@ -460,6 +459,8 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dma_release_channel(dma->chan_tx);
fail_al:
devm_kfree(dev, dma);
+
+ return ret;
}
static void i2c_imx_dma_callback(void *arg)
@@ -1803,6 +1804,13 @@ static int i2c_imx_probe(struct platform_device *pdev)
if (ret == -EPROBE_DEFER)
goto clk_notifier_unregister;
+ /* Init DMA config if supported */
+ ret = i2c_imx_dma_request(i2c_imx, phy_addr);
+ if (ret == -EPROBE_DEFER) {
+ dev_err(&pdev->dev, "DMA not ready, go defer probe!\n");
+ goto clk_notifier_unregister;
+ }
+
/* Add I2C adapter */
ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
if (ret < 0)
@@ -1817,9 +1825,6 @@ static int i2c_imx_probe(struct platform_device *pdev)
i2c_imx->adapter.name);
dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
- /* Init DMA config if supported */
- i2c_imx_dma_request(i2c_imx, phy_addr);
-
return 0; /* Return OK */
clk_notifier_unregister:
--
2.34.1
