rtc-cmos: look for PNP RTC first, then for platform RTC (72f22b1e) · Commits · 戴 / test

We shouldn't rely on "pnp_platform_devices" to tell us whether there is a PNP RTC device. I introduced "pnp_platform_devices", but I think it was a mistake. All it tells us is whether we found any PNPBIOS or PNPACPI devices. Many machines have some PNP devices, but do not describe the RTC via PNP. On those machines, we need to do the platform driver probe to find the RTC. We should just register the PNP driver and see whether it claims anything. If we don't find a PNP RTC, fall back to the platform driver probe. This (in conjunction with the arch/x86/kernel/rtc.c patch to add a platform RTC device when PNP doesn't have one) should resolve these issues: http://bugzilla.kernel.org/show_bug.cgi?id=11580 https://bugzilla.redhat.com/show_bug.cgi?id=451188 Signed-off-by:

Bjorn Helgaas <bjorn.helgaas@hp.com> Acked-by:

Rafael J. Wysocki <rjw@sisk.pl> Acked-by:

David Brownell <dbrownell@users.sourceforge.net> Reported-by:

Rik Theys <rik.theys@esat.kuleuven.be> Reported-by:

<shr_msn@yahoo.com.tw> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-cmos.c

+18 −15

Original line number	Original line	Diff line number	Diff line
	@@ -1120,29 +1120,32 @@ static struct platform_driver cmos_platform_driver = {

	static int __init cmos_init(void)		static int __init cmos_init(void)
	{		{
			int retval = 0;

	#ifdef CONFIG_PNP		#ifdef CONFIG_PNP
	if (pnp_platform_devices)		pnp_register_driver(&cmos_pnp_driver);
	return pnp_register_driver(&cmos_pnp_driver);		#endif
	else
	return platform_driver_probe(&cmos_platform_driver,		if (!cmos_rtc.dev)
	cmos_platform_probe);		retval = platform_driver_probe(&cmos_platform_driver,
	#else
	return platform_driver_probe(&cmos_platform_driver,
	cmos_platform_probe);		cmos_platform_probe);
	#endif /* CONFIG_PNP */
			if (retval == 0)
			return 0;

			#ifdef CONFIG_PNP
			pnp_unregister_driver(&cmos_pnp_driver);
			#endif
			return retval;
	}		}
	module_init(cmos_init);		module_init(cmos_init);

	static void __exit cmos_exit(void)		static void __exit cmos_exit(void)
	{		{
	#ifdef CONFIG_PNP		#ifdef CONFIG_PNP
	if (pnp_platform_devices)
	pnp_unregister_driver(&cmos_pnp_driver);		pnp_unregister_driver(&cmos_pnp_driver);
	else		#endif
	platform_driver_unregister(&cmos_platform_driver);
	#else
	platform_driver_unregister(&cmos_platform_driver);		platform_driver_unregister(&cmos_platform_driver);
	#endif /* CONFIG_PNP */
	}		}
	module_exit(cmos_exit);		module_exit(cmos_exit);

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