On Thu, Sep 22, 2011 at 12:03:35PM -0600, Grant Likely wrote: > On Thu, Sep 22, 2011 at 11:51:32AM -0600, Stephen Warren wrote: > > * Implement an explicit dependency management system within the kernel for > > device suspend/resume, such that I2C bus would not be suspended before > > the sound card that requires it. It is reported that Linus rejected this > > proposal since he wanted suspend ordering to be based on probe ordering. > This really should be revisted. That was in the context of full > system suspend, but we're now in a world of runtime suspend which > absolutely does need dependency tracking or reference counting to get > the ordering right. FWIW this was one of the bigger issues in the PM miniconference in Santa Rosa, though a lot of the discission involved explaining the issues to some of the x86 guys and there wasn't mssive progress on solutions. > > * Enhance device probing such that the ASoC sound card device could defer > > its probing until all required resources were available. This would > > then cause the overall sound card suspend to occur at an appropriate early > > time. Grant Likely was reported to have been working towards this goal. > Yes, I'll send you my current patch for you to look at. One of the > engineers from Linaro is going to be pushing that patch set forward. > However, I don't know if it helps with this problem because I believe > that the suspend order is based on the implicit probe order of > devices, but my patch allows drivers to cause the probe order to get > rearranged at runtime. I don't believe there is a global list showing > the order that devices successfully got probed, but I may be wrong > here. Yes, I'm not convinced it'll change anything here. Though I guess it should be a simple matter of programming to move devices around the list depending on when they probe. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
