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Date: Fri, 5 Apr 2024 14:22:05 -0700
From: Jackson Chui <jacksonchui.qwerty@gmail.com>
To: Alex Elder <elder@ieee.org>
Cc: Johan Hovold <johan@kernel.org>, Alex Elder <elder@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	greybus-dev@lists.linaro.org, linux-staging@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] staging: greybus: Clear up precedence for gcam logging
 macros
Message-ID: <ZhBrff8qkkmum4wc@jc-ubuntu-dev-korn-1>
References: <20240404001627.94858-1-jacksonchui.qwerty@gmail.com>
 <658e1f40-d1eb-4ba7-9ba3-0aa05a1ed06e@ieee.org>
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In-Reply-To: <658e1f40-d1eb-4ba7-9ba3-0aa05a1ed06e@ieee.org>

On Thu, Apr 04, 2024 at 05:05:09PM -0500, Alex Elder wrote:
> On 4/3/24 7:16 PM, Jackson Chui wrote:
> > Reported by checkpatch:
> > 
> > CHECK: Macro argument 'gcam' may be better as '(gcam)' to avoid
> > precedence issues
> 
> I agree with your argument about the way the macro should be
> defined.  But perhaps these gcam_*() functions could just
> be eliminated?
> 
> I see 15 calls to gcam_err(), 1 call to gcam_dbg(), and none
> to gcam_info().  It would be a different patch, but maybe
> you could do that instead?
> 
> 					-Alex
> 
> 
> > 
> > Disambiguates '&' (address-of) operator and '->' operator precedence,
> > accounting for how '(gcam)->bundle->dev' is a 'struct device' and not a
> > 'struct device*', which is required by the dev_{dbg,info,err} driver
> > model diagnostic macros. Issue found by checkpatch.
> > 
> > Signed-off-by: Jackson Chui <jacksonchui.qwerty@gmail.com>
> > ---
> >   drivers/staging/greybus/camera.c | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/staging/greybus/camera.c b/drivers/staging/greybus/camera.c
> > index a8173aa3a995..d82a2d2abdca 100644
> > --- a/drivers/staging/greybus/camera.c
> > +++ b/drivers/staging/greybus/camera.c
> > @@ -180,9 +180,9 @@ static const struct gb_camera_fmt_info *gb_camera_get_format_info(u16 gb_fmt)
> >   #define GB_CAMERA_MAX_SETTINGS_SIZE	8192
> > -#define gcam_dbg(gcam, format...)	dev_dbg(&gcam->bundle->dev, format)
> > -#define gcam_info(gcam, format...)	dev_info(&gcam->bundle->dev, format)
> > -#define gcam_err(gcam, format...)	dev_err(&gcam->bundle->dev, format)
> > +#define gcam_dbg(gcam, format...)	dev_dbg(&((gcam)->bundle->dev), format)
> > +#define gcam_info(gcam, format...)	dev_info(&((gcam)->bundle->dev), format)
> > +#define gcam_err(gcam, format...)	dev_err(&((gcam)->bundle->dev), format)
> >   static int gb_camera_operation_sync_flags(struct gb_connection *connection,
> >   					  int type, unsigned int flags,
>

Thanks for the feedback, Alex!

I thought about refactoring it, but I feel it is worth keeping
the macro around. It acts as an apdater between callers, who 
have 'gcam' and want to log and what the dynamic debug macros 
expect. Without it, the code gets pretty ugly.

Jackson