On 8/15/22 9:06 AM, Heiko Stübner wrote:
> Am Montag, 15. August 2022, 06:12:42 CEST schrieb Samuel Holland:
>> Errors from debugfs are intended to be non-fatal, and should not prevent
>> the driver from probing.
>>
>> Since debugfs file creation is treated as infallible, move it below the
>> parts of the probe function that can fail. This prevents an error
>> elsewhere in the probe function from causing the file to leak. Do the
>> same for the call to of_platform_populate().
>>
>> Finally, checkpatch suggests an octal literal for the file permissions.
>>
>> Fixes: 4af34b572a85 ("drivers: soc: sunxi: Introduce SoC driver to map SRAMs")
>> Fixes: 5828729bebbb ("soc: sunxi: export a regmap for EMAC clock reg on A64")
>> Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
>> Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
>
> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
>
> but one thing below
>
>> ---
>>
>> (no changes since v1)
>>
>> drivers/soc/sunxi/sunxi_sram.c | 13 +++++--------
>> 1 file changed, 5 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/soc/sunxi/sunxi_sram.c b/drivers/soc/sunxi/sunxi_sram.c
>> index a858a37fcdd4..52d07bed7664 100644
>> --- a/drivers/soc/sunxi/sunxi_sram.c
>> +++ b/drivers/soc/sunxi/sunxi_sram.c
>> @@ -332,9 +332,9 @@ static struct regmap_config sunxi_sram_emac_clock_regmap = {
>>
>> static int __init sunxi_sram_probe(struct platform_device *pdev)
>> {
>> - struct dentry *d;
>> struct regmap *emac_clock;
>> const struct sunxi_sramc_variant *variant;
>> + struct device *dev = &pdev->dev;
>>
>> sram_dev = &pdev->dev;
>>
>> @@ -346,13 +346,6 @@ static int __init sunxi_sram_probe(struct platform_device *pdev)
>> if (IS_ERR(base))
>> return PTR_ERR(base);
>>
>> - of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
>> -
>> - d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
>> - &sunxi_sram_fops);
>> - if (!d)
>> - return -ENOMEM;
>> -
>> if (variant->num_emac_clocks > 0) {
>> emac_clock = devm_regmap_init_mmio(&pdev->dev, base,
>> &sunxi_sram_emac_clock_regmap);
>> @@ -361,6 +354,10 @@ static int __init sunxi_sram_probe(struct platform_device *pdev)
>> return PTR_ERR(emac_clock);
>> }
>>
>> + of_platform_populate(dev->of_node, NULL, NULL, dev);
>
> hmm, of_platform_populate() can actually fail [0] it just looks a bit like
> sunxi driver seem to ignore that by {chance, design?} [1] .
>
> So I guess this might want to have handling for probably unlikely
> possible errors instead?
Strictly speaking, neither this driver nor the DE2 bus driver depend on any of
the child nodes having a platform device present or a driver attached. So
failing to populate the child devices should not necessarily prevent this driver
from probing. Possibly it deserves a dev_warn(), but...
I don't think of_platform_populate() can actually fail when passed a valid node.
of_platform_bus_create() calls itself recursively, but otherwise always returns 0.
Regards,
Samuel
> Heiko
>
> [0] https://elixir.bootlin.com/linux/latest/source/drivers/of/platform.c#L463
> [1] https://elixir.bootlin.com/linux/latest/source/drivers/bus/sun50i-de2.c#L22
>> +
>> + debugfs_create_file("sram", 0444, NULL, NULL, &sunxi_sram_fops);
>> +
>> return 0;
>> }
