Re: [PATCH v3 16/22] ACPI: platform_profile: Set profile for all registered handlers

[Ilpo Järvinen]

On Thu, 31 Oct 2024, Mario Limonciello wrote:

> On 10/31/2024 05:25, Ilpo Järvinen wrote:
> > On Wed, 30 Oct 2024, Mario Limonciello wrote:
> > 
> > > If multiple platform profile handlers have been registered then when
> > > setting a profile verify that all profile handlers support the requested
> > > profile and set it to each handler.
> > > 
> > > If this fails for any given handler, revert all profile handlers back to
> > > balanced and log an error into the kernel ring buffer.
> > > 
> > > Tested-by: Matthew Schwartz <matthew.schwartz@xxxxxxxxx>
> > > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> > > ---
> > >   drivers/acpi/platform_profile.c | 25 ++++++++++++++++++++-----
> > >   1 file changed, 20 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/acpi/platform_profile.c
> > > b/drivers/acpi/platform_profile.c
> > > index 90cbc0de4d5bc..c2bb325ba531c 100644
> > > --- a/drivers/acpi/platform_profile.c
> > > +++ b/drivers/acpi/platform_profile.c
> > > @@ -99,6 +99,8 @@ static ssize_t platform_profile_store(struct device
> > > *dev,
> > >   			    struct device_attribute *attr,
> > >   			    const char *buf, size_t count)
> > >   {
> > > +	struct platform_profile_handler *handler;
> > > +	unsigned long choices;
> > >   	int err, i;
> > >     	/* Scan for a matching profile */
> > > @@ -107,16 +109,29 @@ static ssize_t platform_profile_store(struct device
> > > *dev,
> > >   		return -EINVAL;
> > >     	scoped_cond_guard(mutex_intr, return -ERESTARTSYS,
> > > &profile_lock) {
> > > -		if (!cur_profile)
> > > +		if (!platform_profile_is_registered())
> > >   			return -ENODEV;
> > >   -		/* Check that platform supports this profile choice */
> > > -		if (!test_bit(i, cur_profile->choices))
> > > +		/* Check that all handlers support this profile choice */
> > > +		choices = platform_profile_get_choices();
> > > +		if (!test_bit(i, &choices))
> > >   			return -EOPNOTSUPP;
> > >   -		err = cur_profile->profile_set(cur_profile, i);
> > > -		if (err)
> > > +		list_for_each_entry(handler, &platform_profile_handler_list,
> > > list) {
> > > +			err = handler->profile_set(handler, i);
> > > +			if (err) {
> > > +				pr_err("Failed to set profile for handler
> > > %s\n", handler->name);
> > > +				break;
> > > +			}
> > > +		}
> > > +		if (err) {
> > > +			list_for_each_entry_continue_reverse(handler,
> > > &platform_profile_handler_list, list) {
> > 
> > Too long line.
> > 
> > This looks an error rollback though so instead of break inside the loop
> > you could goto into a label at the end of the function and have much less
> > indentation to begin with.
> 
> How does the scoped_cond_guard interact with a goto?  With the jump I had
> guessed it goes out of scope, but I wasn't really sure what the compiler does.
> 
> I guess in the goto label I'll need another scoped_cond_guard()?

Ah, the scope problem is a good point.

Perhaps you could instead add e.g. platform_profile_reset_default() and 
call that before break, both patches that had the rollback did the same 
thing anyway so it can be reused too.

-- 
 i.