* [PATCH] soundwire: fix pm_runtime_get_sync return code checks @ 2019-04-05 7:26 Jan Kotas [not found] ` <367316fa-9d92-2dfc-32c4-3e0e8c76ef43@linux.intel.com> 0 siblings, 1 reply; 4+ messages in thread From: Jan Kotas @ 2019-04-05 7:26 UTC (permalink / raw) To: vkoul, sanyog.r.kale, pierre-louis.bossart Cc: alsa-devel, linux-kernel, Jan Kotas When PM is disabled it returns -EACCES, which is currently threated as an error, and prevents accessing the slave's registers. This patch ignores the -EACCES return value from pm_runtime_get_sync() to let the SoundWire work in systems without runtime PM. Signed-off-by: Jan Kotas <jank@cadence.com> --- drivers/soundwire/bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 1cbfedfc2..6567ff439 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -328,7 +328,7 @@ int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) return ret; ret = pm_runtime_get_sync(slave->bus->dev); - if (ret < 0) + if (ret < 0 && ret != -EACCES) return ret; ret = sdw_transfer(slave->bus, &msg); @@ -356,7 +356,7 @@ int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) return ret; ret = pm_runtime_get_sync(slave->bus->dev); - if (ret < 0) + if (ret < 0 && ret != -EACCES) return ret; ret = sdw_transfer(slave->bus, &msg); -- 2.15.0 ^ permalink raw reply related [flat|nested] 4+ messages in thread
[parent not found: <367316fa-9d92-2dfc-32c4-3e0e8c76ef43@linux.intel.com>]
* Re: [PATCH] soundwire: fix pm_runtime_get_sync return code checks [not found] ` <367316fa-9d92-2dfc-32c4-3e0e8c76ef43@linux.intel.com> @ 2019-04-08 7:12 ` Jan Kotas 2019-04-08 17:43 ` [alsa-devel] " Pierre-Louis Bossart 0 siblings, 1 reply; 4+ messages in thread From: Jan Kotas @ 2019-04-08 7:12 UTC (permalink / raw) To: Pierre-Louis Bossart Cc: Jan Kotas, vkoul, sanyog.r.kale, alsa-devel, linux-kernel, Srinivas Kandagatla > On 5 Apr 2019, at 17:04, Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> wrote: > > On 4/5/19 2:26 AM, Jan Kotas wrote: >> >> >> ret = pm_runtime_get_sync(slave->bus->dev); >> - if (ret < 0) >> + if (ret < 0 && ret != -EACCES) >> > There was a patch submitted on 3/28 by Srinivas Kandagatla who suggested an alternate solution for exactly the same code. > > + if (pm_runtime_enabled(slave->bus->dev)) { > + ret = pm_runtime_get_sync(slave->bus->dev); > + if (ret < 0) > + return ret; > > I am far from an expert on pm_runtime but Srinivas' solution looks more elegant to me. Hello Pierre, Please take a look at this patch, that was my inspiration: https://lists.linuxfoundation.org/pipermail/linux-pm/2011-June/031930.html I also took a look, and it seems the value returned by pm_runtime_get_syncis simply ignored in a lot of places, so checking its value may be excessive. Regards, Jan ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [alsa-devel] [PATCH] soundwire: fix pm_runtime_get_sync return code checks 2019-04-08 7:12 ` Jan Kotas @ 2019-04-08 17:43 ` Pierre-Louis Bossart 2019-04-14 10:26 ` Vinod Koul 0 siblings, 1 reply; 4+ messages in thread From: Pierre-Louis Bossart @ 2019-04-08 17:43 UTC (permalink / raw) To: Jan Kotas Cc: alsa-devel, linux-kernel, vkoul, Srinivas Kandagatla, sanyog.r.kale On 4/8/19 2:12 AM, Jan Kotas wrote: > > >> On 5 Apr 2019, at 17:04, Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> wrote: >> >> On 4/5/19 2:26 AM, Jan Kotas wrote: >>> >>> >>> ret = pm_runtime_get_sync(slave->bus->dev); >>> - if (ret < 0) >>> + if (ret < 0 && ret != -EACCES) >>> >> There was a patch submitted on 3/28 by Srinivas Kandagatla who suggested an alternate solution for exactly the same code. >> >> + if (pm_runtime_enabled(slave->bus->dev)) { >> + ret = pm_runtime_get_sync(slave->bus->dev); >> + if (ret < 0) >> + return ret; >> >> I am far from an expert on pm_runtime but Srinivas' solution looks more elegant to me. > > Hello Pierre, > > Please take a look at this patch, that was my inspiration: > https://lists.linuxfoundation.org/pipermail/linux-pm/2011-June/031930.html The two patches seems to be identical: static inline bool pm_runtime_enabled(struct device *dev) { return !dev->power.disable_depth; } static int rpm_resume() [...] else if (dev->power.disable_depth > 0) retval = -EACCES; However I am still not clear on why this might fail. I can only think of one possible explanation: there is no explicit pm_runtime_enable() in the soundwire code, so maybe the expectation is that the pm_runtime status is inherited from the parent (in the intel case the PCI driver), and that's missing in non-intel configurations? > I also took a look, and it seems the value returned by > pm_runtime_get_syncis simply ignored in a lot of places, > so checking its value may be excessive. But not checking seems careless at best... ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [alsa-devel] [PATCH] soundwire: fix pm_runtime_get_sync return code checks 2019-04-08 17:43 ` [alsa-devel] " Pierre-Louis Bossart @ 2019-04-14 10:26 ` Vinod Koul 0 siblings, 0 replies; 4+ messages in thread From: Vinod Koul @ 2019-04-14 10:26 UTC (permalink / raw) To: Pierre-Louis Bossart Cc: Jan Kotas, alsa-devel, linux-kernel, Srinivas Kandagatla, sanyog.r.kale On 08-04-19, 12:43, Pierre-Louis Bossart wrote: > > > On 4/8/19 2:12 AM, Jan Kotas wrote: > > > > > > > On 5 Apr 2019, at 17:04, Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> wrote: > > > > > > On 4/5/19 2:26 AM, Jan Kotas wrote: > > > > > > > > ret = pm_runtime_get_sync(slave->bus->dev); > > > > - if (ret < 0) > > > > + if (ret < 0 && ret != -EACCES) > > > > > > > There was a patch submitted on 3/28 by Srinivas Kandagatla who suggested an alternate solution for exactly the same code. > > > > > > + if (pm_runtime_enabled(slave->bus->dev)) { > > > + ret = pm_runtime_get_sync(slave->bus->dev); > > > + if (ret < 0) > > > + return ret; > > > > > > I am far from an expert on pm_runtime but Srinivas' solution looks more elegant to me. > > > > Hello Pierre, > > > > Please take a look at this patch, that was my inspiration: > > https://lists.linuxfoundation.org/pipermail/linux-pm/2011-June/031930.html > > The two patches seems to be identical: > > static inline bool pm_runtime_enabled(struct device *dev) > { > return !dev->power.disable_depth; > } > > static int rpm_resume() > [...] > else if (dev->power.disable_depth > 0) > retval = -EACCES; > > > However I am still not clear on why this might fail. > > I can only think of one possible explanation: there is no explicit > pm_runtime_enable() in the soundwire code, so maybe the expectation is that > the pm_runtime status is inherited from the parent (in the intel case the > PCI driver), and that's missing in non-intel configurations? IIRC that needs to be called by the Intel driver and those patches were not upstreamed. So we dont have fully supported PM on upstream yet! > > > I also took a look, and it seems the value returned by > > pm_runtime_get_syncis simply ignored in a lot of places, > > so checking its value may be excessive. > But not checking seems careless at best... -- ~Vinod ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-04-14 10:26 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-04-05 7:26 [PATCH] soundwire: fix pm_runtime_get_sync return code checks Jan Kotas [not found] ` <367316fa-9d92-2dfc-32c4-3e0e8c76ef43@linux.intel.com> 2019-04-08 7:12 ` Jan Kotas 2019-04-08 17:43 ` [alsa-devel] " Pierre-Louis Bossart 2019-04-14 10:26 ` Vinod Koul
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).