[libcamera-devel] [PATCH] libcamera: ipa_manager: Rework error messages when enumerating IPAs

[Laurent Pinchart]

Hi Paul,

On Tue, Sep 17, 2019 at 02:07:03AM -0400, Paul Elder wrote:
> On Sun, Sep 15, 2019 at 11:23:18PM +0300, Laurent Pinchart wrote:
> > When enumerating IPAs, the system IPA directory and all the directories
> > listed in the LIBCAMERA_IPA_MODULE_PATH environment variable are listed
> > in turn. Failing to list any of those directories results in an error
> > message being printed for every failure. This is particularly common
> > when developing libcamera, as IPAs may not have been installed locally.
> > 
> > To avoid unnecessarily worrying error messages, rework the enumeration
> > procedure to only print a message when no IPA can be found at all.
> > Individual missing directories are not considered as an issue anymore.
> > The message is also downgraded from an error to a warning as the
> > situation may still be normal.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  src/libcamera/ipa_manager.cpp | 24 ++++++++++++++++++------
> >  1 file changed, 18 insertions(+), 6 deletions(-)
> > 
> > diff --git a/src/libcamera/ipa_manager.cpp b/src/libcamera/ipa_manager.cpp
> > index 0a908eae6261..f3e08375820c 100644
> > --- a/src/libcamera/ipa_manager.cpp
> > +++ b/src/libcamera/ipa_manager.cpp
> > @@ -94,11 +94,19 @@ LOG_DEFINE_CATEGORY(IPAManager)
> >  
> >  IPAManager::IPAManager()
> >  {
> > -	addDir(IPA_MODULE_DIR);
> > +	unsigned int ipaCount = 0;
> > +	int ret;
> > +
> > +	ret = addDir(IPA_MODULE_DIR);
> > +	if (ret > 0)
> > +		ipaCount += ret;
> >  	const char *modulePaths = utils::secure_getenv("LIBCAMERA_IPA_MODULE_PATH");
> > -	if (!modulePaths)
> > +	if (!modulePaths) {
> > +		LOG(IPAManager, Warning)
> > +			<< "No IPA found in '" IPA_MODULE_DIR "'";
> 
> We need to check ipaCount here, since we could have loaded some IPAs
> from the global dir, and just not have the environment variable
> specified.

Oops, indeed. I'll fix this.

> >  		return;
> > +	}
> >  
> >  	while (1) {
> >  		const char *delim = strchrnul(modulePaths, ':');
> > @@ -106,7 +114,9 @@ IPAManager::IPAManager()
> >  
> >  		if (count) {
> >  			std::string path(modulePaths, count);
> > -			addDir(path.c_str());
> > +			ret = addDir(path.c_str());
> > +			if (ret > 0)
> > +				ipaCount += ret;
> >  		}
> >  
> >  		if (*delim == '\0')
> > @@ -114,6 +124,11 @@ IPAManager::IPAManager()
> >  
> >  		modulePaths += count + 1;
> >  	}
> > +
> > +	if (!ipaCount)
> > +		LOG(IPAManager, Warning)
> > +			<< "No IPA found in '" IPA_MODULE_DIR "' and '"
> > +			<< modulePaths << "'";
> 
> I presume you're fine with modulePaths being printed as-is, as a
> colon-separated list of directories.

I think it's good enough for now, yes.

> >  }
> >  
> >  IPAManager::~IPAManager()
> > @@ -155,9 +170,6 @@ int IPAManager::addDir(const char *libDir)
> >  	dir = opendir(libDir);
> >  	if (!dir) {
> >  		int ret = -errno;
> > -		LOG(IPAManager, Error)
> > -			<< "Invalid path " << libDir << " for IPA modules: "
> > -			<< strerror(-ret);
> >  		return ret;
> 
> Could this be shortened to
> return -errno; ?

Unfortunately not, as LOG() could result in errno being modified. That's
why we have these constructs through the code where we store -errno in
ret.

> >  	}
> 
> With these changes,
> Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>

-- 
Regards,

Laurent Pinchart