From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Date: Mon, 02 Jul 2018 10:06:38 +0000 Subject: Re: [PATCH] fbcon: introduce for_each_registered_fb() helper Message-Id: <048c10a3acb3dec624d1064e84ffd4957648949b.camel@linux.intel.com> List-Id: References: <1530202809-24105-1-git-send-email-ysxie@foxmail.com> <20180702073028.GZ13978@phenom.ffwll.local> In-Reply-To: <20180702073028.GZ13978@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Daniel Vetter Cc: Yisheng Xie , b.zolnierkie@samsung.com, keescook@chromium.org, j.w.r.degoede@gmail.com, david@lechnology.com, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org On Mon, 2018-07-02 at 09:30 +0200, Daniel Vetter wrote: > On Fri, Jun 29, 2018 at 07:20:13PM +0300, Andy Shevchenko wrote: > > On Fri, 2018-06-29 at 00:20 +0800, Yisheng Xie wrote: > > LGTM except macro implementation. That's why I have mentioned > > for_each_pci_bridge() to look at. > > > > > +#define for_each_registered_fb(i) \ > > > + for (i = 0; i < FB_MAX; i++) \ > > > + if (registered_fb[i]) > > > + > > > > This needs to be protected against nested conditionals. > > Otherwise compiler issues a warning and even may generate wrong > > code. > > See for_each_if() in include/drm/drmP.h ... we should probably lift > that > into a general header. The for_each_if() is used all over drm in > iterator > macros, exactly to avoid surprises. Wow, didn't know we have a such. It's a good idea to forelift it for wider use. Yisheng, it seems you may use it in your patch directly. -- Andy Shevchenko Intel Finland Oy