| Message ID | 7cb6e0e039e0935e37c81d0f23d26b0b81ad8cda.1400597170.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 05/20/2014 09:53 AM, Viresh Kumar wrote: > From: Chander Kashyap <k.chander@samsung.com> > > We don't have any protection against addition of duplicate OPPs currently and > in case some code tries to add them it will end up corrupting OPP tables. > > There can be many combinations in which we may end up trying duplicate OPPs: > - both freq and volt are same, but earlier OPP may or may not be active. > - only freq is same and volt is different. > > This patch tries to implement below logic for these cases: > > Return 0 if new OPP was duplicate of existing one (i.e. same freq and volt) and > return -EEXIST if new OPP had same freq but different volt as of an existing OPP > OR if both freq/volt were same but earlier OPP was disabled. > > Signed-off-by: Chander Kashyap <k.chander@samsung.com> > Signed-off-by: Inderpal Singh <inderpal.s@samsung.com> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > V4->V5: > - Mention Return values under 'Return:' clause of doc style comment. > - s/pr_warn/dev_warn > - s/linrao/linaro in my email id :( > > drivers/base/power/opp.c | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c > index 2553867..6a06d43 100644 > --- a/drivers/base/power/opp.c > +++ b/drivers/base/power/opp.c > @@ -394,6 +394,13 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); > * to keep the integrity of the internal data structures. Callers should ensure > * that this function is *NOT* called under RCU protection or in contexts where > * mutex cannot be locked. > + * > + * Returns: s/Returns:/Return:/ -> sorry for being a nitpick.. scripts/kernel-doc uses "Return:" in $section_return > + * 0: On success OR > + * Duplicate OPPs (both freq and volt are same) and opp->available > + * -EEXIST: Freq are same and volt are different OR > + * Duplicate OPPs (both freq and volt are same) and !opp->available > + * -ENOMEM: Memory allocation failure > */ > int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) > { > @@ -443,15 +450,31 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) > new_opp->u_volt = u_volt; > new_opp->available = true; > > - /* Insert new OPP in order of increasing frequency */ > + /* > + * Insert new OPP in order of increasing frequency > + * and discard if already present > + */ > head = &dev_opp->opp_list; > list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) { > - if (new_opp->rate < opp->rate) > + if (new_opp->rate <= opp->rate) > break; > else > head = &opp->node; > } > > + /* Duplicate OPPs ? */ > + if (new_opp->rate == opp->rate) { > + int ret = (new_opp->u_volt == opp->u_volt) && opp->available ? > + 0 : -EEXIST; > + > + dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", > + __func__, opp->rate, opp->u_volt, opp->available, > + new_opp->rate, new_opp->u_volt, new_opp->available); checkpatch --strict showed: --- /tmp/kernel-patch-verify.22670/ptest_check-start 2014-05-20 10:07:15.736147182 -0500 +++ /tmp/kernel-patch-verify.22670/ptest_check-end 2014-05-20 10:07:15.960149013 -0500 @@ -0,0 +1,6 @@ +CHECK: Alignment should match open parenthesis +#68: FILE: drivers/base/power/opp.c:471: ++ dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", ++ __func__, opp->rate, opp->u_volt, opp->available, +If any of these errors are false positives, please report +them to the maintainer, see CHECKPATCH in MAINTAINERS. > + mutex_unlock(&dev_opp_list_lock); > + kfree(new_opp); > + return ret; > + } > + > list_add_rcu(&new_opp->node, head); > mutex_unlock(&dev_opp_list_lock); > > Other than these minor fixes, Acked-by: Nishanth Menon <nm@ti.com>
On Tuesday, May 20, 2014 08:23:28 PM Viresh Kumar wrote: > From: Chander Kashyap <k.chander@samsung.com> > > We don't have any protection against addition of duplicate OPPs currently and > in case some code tries to add them it will end up corrupting OPP tables. > > There can be many combinations in which we may end up trying duplicate OPPs: > - both freq and volt are same, but earlier OPP may or may not be active. > - only freq is same and volt is different. > > This patch tries to implement below logic for these cases: > > Return 0 if new OPP was duplicate of existing one (i.e. same freq and volt) and > return -EEXIST if new OPP had same freq but different volt as of an existing OPP > OR if both freq/volt were same but earlier OPP was disabled. > > Signed-off-by: Chander Kashyap <k.chander@samsung.com> > Signed-off-by: Inderpal Singh <inderpal.s@samsung.com> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > V4->V5: > - Mention Return values under 'Return:' clause of doc style comment. > - s/pr_warn/dev_warn > - s/linrao/linaro in my email id :( > > drivers/base/power/opp.c | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c > index 2553867..6a06d43 100644 > --- a/drivers/base/power/opp.c > +++ b/drivers/base/power/opp.c > @@ -394,6 +394,13 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); > * to keep the integrity of the internal data structures. Callers should ensure > * that this function is *NOT* called under RCU protection or in contexts where > * mutex cannot be locked. > + * > + * Returns: > + * 0: On success OR > + * Duplicate OPPs (both freq and volt are same) and opp->available > + * -EEXIST: Freq are same and volt are different OR > + * Duplicate OPPs (both freq and volt are same) and !opp->available > + * -ENOMEM: Memory allocation failure > */ > int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) > { > @@ -443,15 +450,31 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) > new_opp->u_volt = u_volt; > new_opp->available = true; > > - /* Insert new OPP in order of increasing frequency */ > + /* > + * Insert new OPP in order of increasing frequency > + * and discard if already present > + */ > head = &dev_opp->opp_list; > list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) { > - if (new_opp->rate < opp->rate) > + if (new_opp->rate <= opp->rate) > break; > else > head = &opp->node; > } > > + /* Duplicate OPPs ? */ > + if (new_opp->rate == opp->rate) { > + int ret = (new_opp->u_volt == opp->u_volt) && opp->available ? > + 0 : -EEXIST; The parens are not necessary. And is the direction correct? > + > + dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", > + __func__, opp->rate, opp->u_volt, opp->available, > + new_opp->rate, new_opp->u_volt, new_opp->available); > + mutex_unlock(&dev_opp_list_lock); > + kfree(new_opp); > + return ret; > + } > + > list_add_rcu(&new_opp->node, head); > mutex_unlock(&dev_opp_list_lock); > >
On 21 May 2014 02:39, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: >> + /* Duplicate OPPs ? */ >> + if (new_opp->rate == opp->rate) { >> + int ret = (new_opp->u_volt == opp->u_volt) && opp->available ? >> + 0 : -EEXIST; > > The parens are not necessary. And is the direction correct? What do you mean by direction here ? -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday, May 21, 2014 09:33:42 AM Viresh Kumar wrote: > On 21 May 2014 02:39, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > >> + /* Duplicate OPPs ? */ > >> + if (new_opp->rate == opp->rate) { > >> + int ret = (new_opp->u_volt == opp->u_volt) && opp->available ? > >> + 0 : -EEXIST; > > > > The parens are not necessary. And is the direction correct? > > What do you mean by direction here ? The case in which we want to return 0. Never mind, it's OK. The parens are still not necessary, though.
On 22 May 2014 05:18, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > The case in which we want to return 0. Never mind, it's OK. Ahh yes, It was wrong earlier and fixed during this patch only :) > The parens are still not necessary, though. Already got rid of them and so didn't bother replying :) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 2553867..6a06d43 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -394,6 +394,13 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); * to keep the integrity of the internal data structures. Callers should ensure * that this function is *NOT* called under RCU protection or in contexts where * mutex cannot be locked. + * + * Returns: + * 0: On success OR + * Duplicate OPPs (both freq and volt are same) and opp->available + * -EEXIST: Freq are same and volt are different OR + * Duplicate OPPs (both freq and volt are same) and !opp->available + * -ENOMEM: Memory allocation failure */ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) { @@ -443,15 +450,31 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt) new_opp->u_volt = u_volt; new_opp->available = true; - /* Insert new OPP in order of increasing frequency */ + /* + * Insert new OPP in order of increasing frequency + * and discard if already present + */ head = &dev_opp->opp_list; list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) { - if (new_opp->rate < opp->rate) + if (new_opp->rate <= opp->rate) break; else head = &opp->node; } + /* Duplicate OPPs ? */ + if (new_opp->rate == opp->rate) { + int ret = (new_opp->u_volt == opp->u_volt) && opp->available ? + 0 : -EEXIST; + + dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n", + __func__, opp->rate, opp->u_volt, opp->available, + new_opp->rate, new_opp->u_volt, new_opp->available); + mutex_unlock(&dev_opp_list_lock); + kfree(new_opp); + return ret; + } + list_add_rcu(&new_opp->node, head); mutex_unlock(&dev_opp_list_lock);