| Message ID | 20140805144835.25462.71004.stgit@localhost (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Aug 05, 2014 at 03:48:35PM +0100, Martin Fuzzey wrote: > In order to use the PM hooks for platform specific control we sometimes > need access to the PMU driver data. > > Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com> > --- > arch/arm/kernel/perf_event_cpu.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c > index c09e18e..951a542 100644 > --- a/arch/arm/kernel/perf_event_cpu.c > +++ b/arch/arm/kernel/perf_event_cpu.c > @@ -311,6 +311,7 @@ static int cpu_pmu_device_probe(struct platform_device *pdev) > > cpu_pmu = pmu; > cpu_pmu->plat_device = pdev; > + dev_set_drvdata(&pdev->dev, pmu); I'd rather the platform-specific code used its own structures to keep track of what it's doing. Exposing the PMU like this is almost certainly going to cause us problems later on. Will
On Wed, Aug 06, 2014 at 11:50:29AM +0100, Will Deacon wrote: > On Tue, Aug 05, 2014 at 03:48:35PM +0100, Martin Fuzzey wrote: > > In order to use the PM hooks for platform specific control we sometimes > > need access to the PMU driver data. > > > > Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com> > > --- > > arch/arm/kernel/perf_event_cpu.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c > > index c09e18e..951a542 100644 > > --- a/arch/arm/kernel/perf_event_cpu.c > > +++ b/arch/arm/kernel/perf_event_cpu.c > > @@ -311,6 +311,7 @@ static int cpu_pmu_device_probe(struct platform_device *pdev) > > > > cpu_pmu = pmu; > > cpu_pmu->plat_device = pdev; > > + dev_set_drvdata(&pdev->dev, pmu); > > I'd rather the platform-specific code used its own structures to keep track > of what it's doing. Exposing the PMU like this is almost certainly going to > cause us problems later on. +1 - it's fine for the driver itself to access its private data in the device struct, but this is not supposed to be a mechanism for passing stuff between drivers, or indeed code outside of the driver. A better solution would be a proper API to obtain a reference to this data - and that must have some side effects to protect against the driver being unbound at /any/ moment, and therefore must also have an interface to tell the driver when it can proceed with being unbound.
diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c index c09e18e..951a542 100644 --- a/arch/arm/kernel/perf_event_cpu.c +++ b/arch/arm/kernel/perf_event_cpu.c @@ -311,6 +311,7 @@ static int cpu_pmu_device_probe(struct platform_device *pdev) cpu_pmu = pmu; cpu_pmu->plat_device = pdev; + dev_set_drvdata(&pdev->dev, pmu); if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) { pmu->activated_flags.secure_regs_available =
In order to use the PM hooks for platform specific control we sometimes need access to the PMU driver data. Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com> --- arch/arm/kernel/perf_event_cpu.c | 1 + 1 file changed, 1 insertion(+)