From: Alexandre Belloni <alexandre.belloni@free-electrons.com> To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Julia Lawall <julia.lawall@lip6.fr>, Christophe JAILLET <christophe.jaillet@wanadoo.fr>, perex@perex.cz, tiwai@suse.com, arvind.yadav.cs@gmail.com, nicolas.ferre@microchip.com, broonie@kernel.org, garsilva@embeddedor.com, bhumirks@gmail.com, alsa-devel@alsa-project.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [alsa-devel] [PATCH] ALSA: ac97c: Fix an error handling path in 'atmel_ac97c_probe()' Date: Thu, 31 Aug 2017 11:35:57 +0200 [thread overview] Message-ID: <20170831093557.mhr5txmaiox7gxiq@piout.net> (raw) In-Reply-To: <1504170243.25945.170.camel@linux.intel.com> On 31/08/2017 at 12:04:03 +0300, Andy Shevchenko wrote: > On Thu, 2017-08-31 at 10:23 +0200, Julia Lawall wrote: > > > > On Thu, 31 Aug 2017, Alexandre Belloni wrote: > > > > > On 31/08/2017 at 06:40:42 +0200, Christophe JAILLET wrote: > > > > If 'clk_prepare_enable()' fails, we must release some resources > > > > before > > > > returning. Add a new label in the existing error handling path and > > > > 'goto' > > > > there. > > > > > > > > Fixes: 260ea95cc027 ("ASoC: atmel: ac97c: Handle return value of > > > > clk_prepare_enable.") > > > > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > > > > > > And here is the fallout of the stupid, brainless "fixing" of issues > > > reported by static analysis tools. > > > > > > This clk_prepare_enable will never fail. If it was going to fail, > > > the > > > platform would never boot to a point were it is able to execute that > > > code. It is really annoying to have so much churn for absolutely 0 > > > benefit. > > > > Would it be more productive to put the code back like it was before, > > ie no > > return value and no check, and add a comment to the definition of > > clk_prepare_enable indicating that there are many case where the call > > cannot fail? Grepping through the code suggests that it is about 50- > > 50 on > > checking the return value or not doing so, which might suggest that > > checking the value is often not required. > > I didn't look into the code, though speculating it might be the case > when CLK framework is not enabled, though many drivers are dependent to > it, so, it would never fail in such cases. It is not the case, it would return 0. Anyway, this will not happen because that driver depends on ARCH_AT91 which selects COMMON_CLK_AT91 which selects COMMON_CLK. > Nevertheless there might be > other cases for CLK API to fail. > The only case would be for a clock to be enabled without being prepared and this will never happen because clk_prepare_enable is used. This call will just never fail. -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
WARNING: multiple messages have this Message-ID (diff)
From: Alexandre Belloni <alexandre.belloni@free-electrons.com> To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Julia Lawall <julia.lawall@lip6.fr>, Christophe JAILLET <christophe.jaillet@wanadoo.fr>, perex@perex.cz, tiwai@suse.com, arvind.yadav.cs@gmail.com, nicolas.ferre@microchip.com, broonie@kernel.org, garsilva@embeddedor.com, bhumirks@gmail.com, alsa-devel@alsa-project.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [alsa-devel] [PATCH] ALSA: ac97c: Fix an error handling path in 'atmel_ac97c_probe()' Date: Thu, 31 Aug 2017 09:35:57 +0000 [thread overview] Message-ID: <20170831093557.mhr5txmaiox7gxiq@piout.net> (raw) In-Reply-To: <1504170243.25945.170.camel@linux.intel.com> On 31/08/2017 at 12:04:03 +0300, Andy Shevchenko wrote: > On Thu, 2017-08-31 at 10:23 +0200, Julia Lawall wrote: > > > > On Thu, 31 Aug 2017, Alexandre Belloni wrote: > > > > > On 31/08/2017 at 06:40:42 +0200, Christophe JAILLET wrote: > > > > If 'clk_prepare_enable()' fails, we must release some resources > > > > before > > > > returning. Add a new label in the existing error handling path and > > > > 'goto' > > > > there. > > > > > > > > Fixes: 260ea95cc027 ("ASoC: atmel: ac97c: Handle return value of > > > > clk_prepare_enable.") > > > > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > > > > > > And here is the fallout of the stupid, brainless "fixing" of issues > > > reported by static analysis tools. > > > > > > This clk_prepare_enable will never fail. If it was going to fail, > > > the > > > platform would never boot to a point were it is able to execute that > > > code. It is really annoying to have so much churn for absolutely 0 > > > benefit. > > > > Would it be more productive to put the code back like it was before, > > ie no > > return value and no check, and add a comment to the definition of > > clk_prepare_enable indicating that there are many case where the call > > cannot fail? Grepping through the code suggests that it is about 50- > > 50 on > > checking the return value or not doing so, which might suggest that > > checking the value is often not required. > > I didn't look into the code, though speculating it might be the case > when CLK framework is not enabled, though many drivers are dependent to > it, so, it would never fail in such cases. It is not the case, it would return 0. Anyway, this will not happen because that driver depends on ARCH_AT91 which selects COMMON_CLK_AT91 which selects COMMON_CLK. > Nevertheless there might be > other cases for CLK API to fail. > The only case would be for a clock to be enabled without being prepared and this will never happen because clk_prepare_enable is used. This call will just never fail. -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2017-08-31 9:36 UTC|newest] Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-08-31 4:40 [PATCH] ALSA: ac97c: Fix an error handling path in 'atmel_ac97c_probe()' Christophe JAILLET 2017-08-31 4:40 ` Christophe JAILLET 2017-08-31 4:40 ` Christophe JAILLET 2017-08-31 8:10 ` [alsa-devel] " Alexandre Belloni 2017-08-31 8:10 ` Alexandre Belloni 2017-08-31 8:10 ` [alsa-devel] " Alexandre Belloni 2017-08-31 8:23 ` Julia Lawall 2017-08-31 8:23 ` Julia Lawall 2017-08-31 8:23 ` [alsa-devel] " Julia Lawall 2017-08-31 9:04 ` Andy Shevchenko 2017-08-31 9:04 ` Andy Shevchenko 2017-08-31 9:04 ` [alsa-devel] " Andy Shevchenko 2017-08-31 9:35 ` Alexandre Belloni [this message] 2017-08-31 9:35 ` Alexandre Belloni 2017-08-31 9:38 ` Andy Shevchenko 2017-08-31 9:38 ` Andy Shevchenko 2017-08-31 9:57 ` Alexandre Belloni 2017-08-31 9:57 ` Alexandre Belloni 2017-08-31 9:57 ` [alsa-devel] " Alexandre Belloni 2017-08-31 9:56 ` Alexandre Belloni 2017-08-31 9:56 ` Alexandre Belloni 2017-08-31 9:56 ` [alsa-devel] " Alexandre Belloni 2017-08-31 10:13 ` Takashi Iwai 2017-08-31 10:13 ` Takashi Iwai 2017-08-31 10:13 ` [alsa-devel] " Takashi Iwai 2017-08-31 10:19 ` Alexandre Belloni 2017-08-31 10:19 ` Alexandre Belloni 2017-08-31 10:23 ` Takashi Iwai 2017-08-31 10:23 ` Takashi Iwai 2017-08-31 10:23 ` Takashi Iwai 2017-08-31 10:37 ` Mark Brown 2017-08-31 10:37 ` Mark Brown 2017-08-31 10:37 ` [alsa-devel] " Mark Brown 2017-08-31 10:49 ` Takashi Iwai 2017-08-31 10:49 ` Takashi Iwai 2017-08-31 10:19 ` Mark Brown 2017-08-31 10:19 ` Mark Brown 2017-08-31 10:19 ` [alsa-devel] " Mark Brown 2017-08-31 10:31 ` Takashi Iwai 2017-08-31 10:31 ` Takashi Iwai 2017-08-31 10:31 ` [alsa-devel] " Takashi Iwai 2017-08-31 10:38 ` Mark Brown 2017-08-31 10:38 ` Mark Brown 2017-08-31 10:38 ` [alsa-devel] " Mark Brown 2017-08-31 19:08 ` Christophe JAILLET 2017-08-31 19:08 ` Christophe JAILLET 2017-08-31 19:08 ` Christophe JAILLET 2017-08-31 20:50 ` Alexandre Belloni 2017-08-31 20:50 ` Alexandre Belloni 2017-08-31 21:07 ` Julia Lawall 2017-08-31 21:07 ` Julia Lawall 2017-08-31 21:07 ` Julia Lawall 2017-08-31 11:55 ` Applied "ALSA: ac97c: Fix an error handling path in 'atmel_ac97c_probe()'" to the asoc tree Mark Brown 2017-08-31 11:55 ` Mark Brown 2017-08-31 11:55 ` Mark Brown
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20170831093557.mhr5txmaiox7gxiq@piout.net \ --to=alexandre.belloni@free-electrons.com \ --cc=alsa-devel@alsa-project.org \ --cc=andriy.shevchenko@linux.intel.com \ --cc=arvind.yadav.cs@gmail.com \ --cc=bhumirks@gmail.com \ --cc=broonie@kernel.org \ --cc=christophe.jaillet@wanadoo.fr \ --cc=garsilva@embeddedor.com \ --cc=julia.lawall@lip6.fr \ --cc=kernel-janitors@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=nicolas.ferre@microchip.com \ --cc=perex@perex.cz \ --cc=tiwai@suse.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.