From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Wed, 15 Jul 2015 16:54:33 +0200 Subject: [PATCH] dmaengine: fsl-edma: add PM suspend/resume support In-Reply-To: References: <1436952778-28000-1-git-send-email-yao.yuan@freescale.com> <3074236.7KNCYXgBBY@wuerfel> Message-ID: <2042080.Y9rzRSQLpW@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wednesday 15 July 2015 10:29:55 Yao Yuan wrote: > Hi Arnd, > > Thanks for your review. > And can you give me more information? > In my opinion, The fsl_edma_pm_state will just be used when CONFIG_PM support. So why not use the #ifdefs to remove the > unnecessary code? Since the PM will not be selected in many use cases. I would consider code readability more important than saving a few instructions, and the #ifdef interrupts the reading flow. Another aspect is that the compiler does not produce warnings for incorrect code in an #ifdef, so we try to use e.g. 'if (IS_ENABLED(CONFIG_FOO))' instead of '#ifdef CONFIG_FOO' wherever possible. Arnd