* pm_runtime functions and IS_ERR_VALUE (was Re: [PATCH v6] ARM: omap: edma: add suspend suspend/resume hooks) [not found] ` <5295F99F.6010203@ti.com> @ 2013-11-27 23:15 ` Nishanth Menon 2013-11-28 13:13 ` Rafael J. Wysocki 0 siblings, 1 reply; 2+ messages in thread From: Nishanth Menon @ 2013-11-27 23:15 UTC (permalink / raw) To: Sekhar Nori, rjw Cc: Daniel Mack, linux-omap, joelf, gururaja.hebbar, balajitk, s.neumann, Russ.Dill, vaibhav.bedia, linux-arm-kernel, Kevin Hilman, Julia.Lawall, Gilles.Muller, nicolas.palix, mmarek, linux-kernel, cocci, rmk+kernel, linux-pm Change in subject line + wider forum On 19:24-20131127, Sekhar Nori wrote: > On Wednesday 27 November 2013 07:17 PM, Daniel Mack wrote: > > On 11/27/2013 02:35 PM, Sekhar Nori wrote: > >> On Monday 18 November 2013 03:49 AM, Daniel Mack wrote: > >>> +static int edma_pm_suspend(struct device *dev) > >>> +{ > >>> + int j, r; > >>> + > >>> + r = pm_runtime_get_sync(dev); > >>> + if (IS_ERR_VALUE(r)) { > >> > >> So IS_ERR_VALUE() is only for functions which may return a negative > >> number outside of MAX_ERRNO as a success indication. > >> pm_runtime_get_sync() does not appear to be one of them so just use" > >> > >> if (r < 0) { .. } > > > > That's true. Thanks for catching this, I'll fix it. However, grepping > > through the tree, there are quite a lot places where the same mistake is > > made. > > Yes, this is a common fallacy. Russell cleaned up a bunch of these a > while back. Thinking a little more on this front, to prevent recurrence and fixing the ones we already have, how about something like the following patch? For example, on 3.13-rc1, with omap2plus_defconfig, I see the following: http://pastebin.mozilla.org/3681911 -->8-- >From b7946d214fab72b2e18cd67eec01c377f1cddee8 Mon Sep 17 00:00:00 2001 From: Nishanth Menon <nm@ti.com> Date: Wed, 27 Nov 2013 17:01:20 -0600 Subject: [RFC PATCH] scripts: Coccinelle script for pm_runtime_* return checks with IS_ERR_VALUE As indicated by Sekhar in [1], there seems to be a tendency to use IS_ERR_VALUE to check the error result for pm_runtime_* functions which make no sense considering commit c48cd65 (ARM: OMAP: use consistent error checking) - the error values can either be < 0 for error OR 0, 1 in cases where we have success. So, setup a coccinelle script to help identify the same. [1] http://marc.info/?t=138472678100003&r=1&w=2 Cc: Russell King <rmk+kernel@arm.linux.org.uk> Reported-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Nishanth Menon <nm@ti.com> --- scripts/coccinelle/api/pm_runtime.cocci | 109 +++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 scripts/coccinelle/api/pm_runtime.cocci diff --git a/scripts/coccinelle/api/pm_runtime.cocci b/scripts/coccinelle/api/pm_runtime.cocci new file mode 100644 index 0000000..f01789e --- /dev/null +++ b/scripts/coccinelle/api/pm_runtime.cocci @@ -0,0 +1,109 @@ +/// Make sure pm_runtime_* calls does not use unnecessary IS_ERR_VALUE +// +// Keywords: pm_runtime +// Confidence: Medium +// Copyright (C) 2013 Texas Instruments Incorporated - GPLv2. +// URL: http://coccinelle.lip6.fr/ +// Options: --include-headers + +virtual patch +virtual context +virtual org +virtual report + +//---------------------------------------------------------- +// Detection +//---------------------------------------------------------- + +@runtime_bad_err_handle exists@ +expression ret; +@@ +( +ret = \(pm_runtime_idle\| + pm_runtime_suspend\| + pm_runtime_autosuspend\| + pm_runtime_resume\| + pm_request_idle\| + pm_request_resume\| + pm_request_autosuspend\| + pm_runtime_get\| + pm_runtime_get_sync\| + pm_runtime_put\| + pm_runtime_put_autosuspend\| + pm_runtime_put_sync\| + pm_runtime_put_sync_suspend\| + pm_runtime_put_sync_autosuspend\| + pm_runtime_set_active\| + pm_schedule_suspend\| + pm_runtime_barrier\| + pm_generic_runtime_suspend\| + pm_generic_runtime_resume\)(...); +... +IS_ERR_VALUE(ret) +... +) + +//---------------------------------------------------------- +// For context mode +//---------------------------------------------------------- + +@depends on runtime_bad_err_handle && context@ +identifier pm_runtime_api; +expression ret; +@@ +( +ret = pm_runtime_api(...); +... +* IS_ERR_VALUE(ret) +... +) + +//---------------------------------------------------------- +// For patch mode +//---------------------------------------------------------- + +@depends on runtime_bad_err_handle && patch@ +identifier pm_runtime_api; +expression ret; +@@ +( +ret = pm_runtime_api(...); +... +- IS_ERR_VALUE(ret) ++ ret < 0 +... +) + +//---------------------------------------------------------- +// For org and report mode +//---------------------------------------------------------- + +@r depends on runtime_bad_err_handle exists@ +position p1, p2; +identifier pm_runtime_api; +expression ret; +@@ +( +ret = pm_runtime_api@p1(...); +... +IS_ERR_VALUE@p2(ret) +... +) + +@script:python depends on org@ +p1 << r.p1; +p2 << r.p2; +pm_runtime_api << r.pm_runtime_api; +@@ + +cocci.print_main(pm_runtime_api,p1) +cocci.print_secs("IS_ERR_VALUE",p2) + +@script:python depends on report@ +p1 << r.p1; +p2 << r.p2; +pm_runtime_api << r.pm_runtime_api; +@@ + +msg = "%s returns < 0 as error. Unecessary IS_ERR_VALUE at line %s" % (pm_runtime_api, p2[0].line) +coccilib.report.print_report(p1[0],msg) -- 1.7.9.5 -- Regards, Nishanth Menon ^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: pm_runtime functions and IS_ERR_VALUE (was Re: [PATCH v6] ARM: omap: edma: add suspend suspend/resume hooks) 2013-11-27 23:15 ` pm_runtime functions and IS_ERR_VALUE (was Re: [PATCH v6] ARM: omap: edma: add suspend suspend/resume hooks) Nishanth Menon @ 2013-11-28 13:13 ` Rafael J. Wysocki 0 siblings, 0 replies; 2+ messages in thread From: Rafael J. Wysocki @ 2013-11-28 13:13 UTC (permalink / raw) To: Nishanth Menon Cc: Sekhar Nori, Daniel Mack, linux-omap, joelf, gururaja.hebbar, balajitk, s.neumann, Russ.Dill, vaibhav.bedia, linux-arm-kernel, Kevin Hilman, Julia.Lawall, Gilles.Muller, nicolas.palix, mmarek, linux-kernel, cocci, rmk+kernel, linux-pm On Wednesday, November 27, 2013 05:15:41 PM Nishanth Menon wrote: > Change in subject line + wider forum > > On 19:24-20131127, Sekhar Nori wrote: > > On Wednesday 27 November 2013 07:17 PM, Daniel Mack wrote: > > > On 11/27/2013 02:35 PM, Sekhar Nori wrote: > > >> On Monday 18 November 2013 03:49 AM, Daniel Mack wrote: > > >>> +static int edma_pm_suspend(struct device *dev) > > >>> +{ > > >>> + int j, r; > > >>> + > > >>> + r = pm_runtime_get_sync(dev); > > >>> + if (IS_ERR_VALUE(r)) { > > >> > > >> So IS_ERR_VALUE() is only for functions which may return a negative > > >> number outside of MAX_ERRNO as a success indication. > > >> pm_runtime_get_sync() does not appear to be one of them so just use" > > >> > > >> if (r < 0) { .. } > > > > > > That's true. Thanks for catching this, I'll fix it. However, grepping > > > through the tree, there are quite a lot places where the same mistake is > > > made. > > > > Yes, this is a common fallacy. Russell cleaned up a bunch of these a > > while back. > > Thinking a little more on this front, to prevent recurrence and fixing > the ones we already have, how about something like the following > patch? Looks reasonable - if the result survives the auto build testing. :-) Thanks! > For example, on 3.13-rc1, with omap2plus_defconfig, I see the following: > http://pastebin.mozilla.org/3681911 > > -->8-- > From b7946d214fab72b2e18cd67eec01c377f1cddee8 Mon Sep 17 00:00:00 2001 > From: Nishanth Menon <nm@ti.com> > Date: Wed, 27 Nov 2013 17:01:20 -0600 > Subject: [RFC PATCH] scripts: Coccinelle script for pm_runtime_* return checks > with IS_ERR_VALUE > > As indicated by Sekhar in [1], there seems to be a tendency to use > IS_ERR_VALUE to check the error result for pm_runtime_* functions which > make no sense considering commit c48cd65 (ARM: OMAP: use consistent > error checking) - the error values can either be < 0 for error OR > 0, 1 in cases where we have success. > > So, setup a coccinelle script to help identify the same. > > [1] http://marc.info/?t=138472678100003&r=1&w=2 > > Cc: Russell King <rmk+kernel@arm.linux.org.uk> > Reported-by: Sekhar Nori <nsekhar@ti.com> > Signed-off-by: Nishanth Menon <nm@ti.com> > --- > scripts/coccinelle/api/pm_runtime.cocci | 109 +++++++++++++++++++++++++++++++ > 1 file changed, 109 insertions(+) > create mode 100644 scripts/coccinelle/api/pm_runtime.cocci > > diff --git a/scripts/coccinelle/api/pm_runtime.cocci b/scripts/coccinelle/api/pm_runtime.cocci > new file mode 100644 > index 0000000..f01789e > --- /dev/null > +++ b/scripts/coccinelle/api/pm_runtime.cocci > @@ -0,0 +1,109 @@ > +/// Make sure pm_runtime_* calls does not use unnecessary IS_ERR_VALUE > +// > +// Keywords: pm_runtime > +// Confidence: Medium > +// Copyright (C) 2013 Texas Instruments Incorporated - GPLv2. > +// URL: http://coccinelle.lip6.fr/ > +// Options: --include-headers > + > +virtual patch > +virtual context > +virtual org > +virtual report > + > +//---------------------------------------------------------- > +// Detection > +//---------------------------------------------------------- > + > +@runtime_bad_err_handle exists@ > +expression ret; > +@@ > +( > +ret = \(pm_runtime_idle\| > + pm_runtime_suspend\| > + pm_runtime_autosuspend\| > + pm_runtime_resume\| > + pm_request_idle\| > + pm_request_resume\| > + pm_request_autosuspend\| > + pm_runtime_get\| > + pm_runtime_get_sync\| > + pm_runtime_put\| > + pm_runtime_put_autosuspend\| > + pm_runtime_put_sync\| > + pm_runtime_put_sync_suspend\| > + pm_runtime_put_sync_autosuspend\| > + pm_runtime_set_active\| > + pm_schedule_suspend\| > + pm_runtime_barrier\| > + pm_generic_runtime_suspend\| > + pm_generic_runtime_resume\)(...); > +... > +IS_ERR_VALUE(ret) > +... > +) > + > +//---------------------------------------------------------- > +// For context mode > +//---------------------------------------------------------- > + > +@depends on runtime_bad_err_handle && context@ > +identifier pm_runtime_api; > +expression ret; > +@@ > +( > +ret = pm_runtime_api(...); > +... > +* IS_ERR_VALUE(ret) > +... > +) > + > +//---------------------------------------------------------- > +// For patch mode > +//---------------------------------------------------------- > + > +@depends on runtime_bad_err_handle && patch@ > +identifier pm_runtime_api; > +expression ret; > +@@ > +( > +ret = pm_runtime_api(...); > +... > +- IS_ERR_VALUE(ret) > ++ ret < 0 > +... > +) > + > +//---------------------------------------------------------- > +// For org and report mode > +//---------------------------------------------------------- > + > +@r depends on runtime_bad_err_handle exists@ > +position p1, p2; > +identifier pm_runtime_api; > +expression ret; > +@@ > +( > +ret = pm_runtime_api@p1(...); > +... > +IS_ERR_VALUE@p2(ret) > +... > +) > + > +@script:python depends on org@ > +p1 << r.p1; > +p2 << r.p2; > +pm_runtime_api << r.pm_runtime_api; > +@@ > + > +cocci.print_main(pm_runtime_api,p1) > +cocci.print_secs("IS_ERR_VALUE",p2) > + > +@script:python depends on report@ > +p1 << r.p1; > +p2 << r.p2; > +pm_runtime_api << r.pm_runtime_api; > +@@ > + > +msg = "%s returns < 0 as error. Unecessary IS_ERR_VALUE at line %s" % (pm_runtime_api, p2[0].line) > +coccilib.report.print_report(p1[0],msg) > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. ^ permalink raw reply [flat|nested] 2+ messages in thread
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2013-11-27 23:15 ` pm_runtime functions and IS_ERR_VALUE (was Re: [PATCH v6] ARM: omap: edma: add suspend suspend/resume hooks) Nishanth Menon
2013-11-28 13:13 ` Rafael J. Wysocki
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