If the dma controller is not yet probed, defer i2c probe.
The error path in probe was slightly modified (no functional change)
to avoid triggering this WARN_ON():
"cg-pll0-div1 already disabled
WARNING: CPU: 1 PID: 1 at drivers/clk/clk.c:828 clk_core_disable+0xa8/0xb0"
Signed-off-by: Laurentiu Tudor <[email protected]>
---
drivers/i2c/busses/i2c-imx.c | 45 +++++++++++++++++++++---------------
1 file changed, 27 insertions(+), 18 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index fa9ad53845d9..5a28d25ff9b6 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -273,8 +273,8 @@ static inline unsigned char imx_i2c_read_reg(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;
@@ -283,11 +283,12 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
if (!dma)
- return;
+ return -ENOMEM;
- dma->chan_tx = dma_request_slave_channel(dev, "tx");
- if (!dma->chan_tx) {
- dev_dbg(dev, "can't request DMA tx channel\n");
+ dma->chan_tx = dma_request_slave_channel_reason(dev, "tx");
+ if (IS_ERR(dma->chan_tx)) {
+ ret = PTR_ERR(dma->chan_tx);
+ dma->chan_tx = NULL;
goto fail_al;
}
@@ -301,10 +302,10 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dev_dbg(dev, "can't configure tx channel\n");
goto fail_tx;
}
-
- dma->chan_rx = dma_request_slave_channel(dev, "rx");
- if (!dma->chan_rx) {
- dev_dbg(dev, "can't request DMA rx channel\n");
+ dma->chan_rx = dma_request_slave_channel_reason(dev, "rx");
+ if (IS_ERR(dma->chan_rx)) {
+ ret = PTR_ERR(dma->chan_rx);
+ dma->chan_rx = NULL;
goto fail_tx;
}
@@ -324,7 +325,7 @@ 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);
@@ -332,7 +333,8 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dma_release_channel(dma->chan_tx);
fail_al:
devm_kfree(dev, dma);
- dev_info(dev, "can't use DMA, using PIO instead.\n");
+
+ return ret;
}
static void i2c_imx_dma_callback(void *arg)
@@ -1106,7 +1108,8 @@ static int i2c_imx_probe(struct platform_device *pdev)
pdev->name, i2c_imx);
if (ret) {
dev_err(&pdev->dev, "can't claim irq %d\n", irq);
- goto clk_disable;
+ clk_disable_unprepare(i2c_imx->clk);
+ return ret;
}
/* Init queue */
@@ -1156,17 +1159,25 @@ static int i2c_imx_probe(struct platform_device *pdev)
pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
+ /* Init DMA config if supported */
+ ret = i2c_imx_dma_request(i2c_imx, phy_addr);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_info(&pdev->dev, "can't use DMA, using PIO instead.\n");
+ else
+ goto del_adapter;
+ }
+
dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res);
dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
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 */
+del_adapter:
+ i2c_del_adapter(&i2c_imx->adapter);
clk_notifier_unregister:
clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
rpm_disable:
@@ -1175,8 +1186,6 @@ static int i2c_imx_probe(struct platform_device *pdev)
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_dont_use_autosuspend(&pdev->dev);
-clk_disable:
- clk_disable_unprepare(i2c_imx->clk);
return ret;
}
--
2.17.1
Hi,
On Tue, Jan 15, 2019 at 04:03:32PM +0200, Laurentiu Tudor wrote:
> If the dma controller is not yet probed, defer i2c probe.
> The error path in probe was slightly modified (no functional change)
> to avoid triggering this WARN_ON():
> "cg-pll0-div1 already disabled
> WARNING: CPU: 1 PID: 1 at drivers/clk/clk.c:828 clk_core_disable+0xa8/0xb0"
>
> Signed-off-by: Laurentiu Tudor <[email protected]>
I just applied this series to i2c/for-next:
http://patchwork.ozlabs.org/project/linux-i2c/list/?series=85099&state=*
I haven't checked carefully but maybe it fixes/changes your issue? If
not, your patch most likely will need a rebase on top of the above.
Thanks,
Wolfram
Hello,
On 15.01.2019 23:55, Wolfram Sang wrote:
> Hi,
>
> On Tue, Jan 15, 2019 at 04:03:32PM +0200, Laurentiu Tudor wrote:
>> If the dma controller is not yet probed, defer i2c probe.
>> The error path in probe was slightly modified (no functional change)
>> to avoid triggering this WARN_ON():
>> "cg-pll0-div1 already disabled
>> WARNING: CPU: 1 PID: 1 at drivers/clk/clk.c:828 clk_core_disable+0xa8/0xb0"
>>
>> Signed-off-by: Laurentiu Tudor <[email protected]>
>
> I just applied this series to i2c/for-next:
>
> http://patchwork.ozlabs.org/project/linux-i2c/list/?series=85099&state=*
>
> I haven't checked carefully but maybe it fixes/changes your issue?
Not really as it doesn't seem to defer probing until the dma controller
gets probed.
> If not, your patch most likely will need a rebase on top of the above.
Will rebase on latest i2c tree and re-send.
---
Best Regards, Laurentiu