RE: [PATCH v7 3/4] firmware: arm_scmi: Add SCMI v3.2 pincontrol protocol basic support

[Peng Fan]

Hi Andy

> Subject: Re: [PATCH v7 3/4] firmware: arm_scmi: Add SCMI v3.2 pincontrol
> protocol basic support
> 
> On Tue, Apr 02, 2024 at 10:22:23AM +0800, Peng Fan (OSS) wrote:
> 
> ...
> 
> > +#include <linux/module.h>
> > +#include <linux/scmi_protocol.h>
> > +#include <linux/slab.h>
> 
> Please, follow IWYU principle, a lot of headers are missed.

ok. I will try to figure out. BTW, is there an easy way to filter
out what is missed?

> 
> > +#include "common.h"
> > +#include "protocols.h"
> 
> ...
> 
> > +		ret = scmi_pinctrl_get_pin_info(ph, selector,
> > +						&pi->pins[selector]);
> 
> It's netter as a single line.

I try to follow 80 max chars per SCMI coding style. If Sudeep and Cristian
is ok, I could use a single line.

> 
> > +		if (ret)
> > +			return ret;
> > +	}
> 
> ...
> 
> > +static int scmi_pinctrl_protocol_init(const struct
> > +scmi_protocol_handle *ph) {
> > +	int ret;
> > +	u32 version;
> > +	struct scmi_pinctrl_info *pinfo;
> > +
> > +	ret = ph->xops->version_get(ph, &version);
> > +	if (ret)
> > +		return ret;
> > +
> > +	dev_dbg(ph->dev, "Pinctrl Version %d.%d\n",
> > +		PROTOCOL_REV_MAJOR(version),
> PROTOCOL_REV_MINOR(version));
> > +
> > +	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
> > +	if (!pinfo)
> > +		return -ENOMEM;
> > +
> > +	ret = scmi_pinctrl_attributes_get(ph, pinfo);
> > +	if (ret)
> > +		return ret;
> > +
> > +	pinfo->pins = devm_kcalloc(ph->dev, pinfo->nr_pins,
> > +				   sizeof(*pinfo->pins), GFP_KERNEL);
> > +	if (!pinfo->pins)
> > +		return -ENOMEM;
> > +
> > +	pinfo->groups = devm_kcalloc(ph->dev, pinfo->nr_groups,
> > +				     sizeof(*pinfo->groups), GFP_KERNEL);
> > +	if (!pinfo->groups)
> > +		return -ENOMEM;
> > +
> > +	pinfo->functions = devm_kcalloc(ph->dev, pinfo->nr_functions,
> > +					sizeof(*pinfo->functions),
> GFP_KERNEL);
> > +	if (!pinfo->functions)
> > +		return -ENOMEM;
> > +
> > +	pinfo->version = version;
> > +
> > +	return ph->set_priv(ph, pinfo, version);
> 
> Same comments as per previous version. devm_ here is simply wrong.
> It breaks the order of freeing resources.
> 
> I.o.w. I see *no guarantee* that these init-deinit functions will be properly
> called from the respective probe-remove. Moreover the latter one may also
> have its own devm allocations (which are rightfully placed) and you get
> completely out of control the resource management.

I see an old thread.
https://lore.kernel.org/linux-arm-kernel/ZJ78hBcjAhiU+ZBO@e120937-lin/#t

The free in deinit is not to free the ones alloced in init, it is to free the ones
alloced such as in scmi_pinctrl_get_function_info

Thanks,
Peng.

> 
> > +}
> 
> --
> With Best Regards,
> Andy Shevchenko
>