On Mon, Dec 20, 2021 at 9:31 PM Pavel Machek pavel@ucw.cz wrote:
From: Randy Dunlap rdunlap@infradead.org
[ Upstream commit 1dc2f2b81a6a9895da59f3915760f6c0c3074492 ]
The hyperv utilities use PTP clock interfaces and should depend a a kconfig symbol such that they will be built as a loadable module or builtin so that linker errors do not happen.
Prevents these build errors:
ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit': hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister' ld: drivers/hv/hv_util.o: in function `hv_timesync_init': hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register'
This is bad idea for 4.19:
+++ b/drivers/hv/Kconfig @@ -16,6 +16,7 @@ config HYPERV_TSCPAGE config HYPERV_UTILS tristate "Microsoft Hyper-V Utilities driver" depends on HYPERV && CONNECTOR && NLS
depends on PTP_1588_CLOCK_OPTIONAL help Select this option to enable the Hyper-V Utilities.grep -ri PTP_1588_CLOCK_OPTIONAL .
Results in no result in 4.19. So this will break hyperv. No results in 5.10, either, so it is bad idea there, too.
Right, this doesn't work, but the bug does exist anyway, and could be fixed by listing the dependency explicitly as
depends on PTP_1588_CLOCK || PTP_1588_CLOCK=n
The PTP_1588_CLOCK_OPTIONAL was added as a shortcut to avoid the odd Kconfig syntax that most developers struggle with understanding at first.
Arnd