From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Fri, 2 Oct 2015 13:48:27 -0500 Subject: Dropping "depends on SMP" for HAVE_ARM_TWD -- take 2 In-Reply-To: <20151002180255.GK12338@codeaurora.org> References: <560E53E3.7070207@free.fr> <560E8584.8000207@free.fr> <20151002180255.GK12338@codeaurora.org> Message-ID: <20151002184827.GB5552@saruman.tx.rr.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On Fri, Oct 02, 2015 at 11:02:55AM -0700, Stephen Boyd wrote: > On 10/02, Mason wrote: > > [ Adding original reporter ] > > > > On 02/10/2015 11:52, Mason wrote: > > > > > [ take 1 was sent on 2015-03-26 ] > > > > > > Hello everyone, > > > > > > In http://thread.gmane.org/gmane.linux.ports.arm.kernel/389931/focus=392348 > > > Stephen Boyd wrote: > > > > > >> I don't see any problem with the TWD dropping the dependency on SMP. > > >> The code should work the same on a UP configuration [...] > > > > > > And Arnd recently said: > > > > > >> I think this has come up before and should be fixed. Could you > > >> send a patch that allows using TWD in uniprocessor configurations? > > > > > > Basically, this means reverting Shawn Guo's 904464b91eca patch. > > > and removing "depends on SMP" for HAVE_ARM_TWD. > > > > > > However, Shawn's patch fixed an issue, therefore it seems likely > > > that simply reverting is not the proper solution? > > > > > > What should I do? > > > > For reference, the warning used to be: > > > > ------------[ cut here ]------------ > > WARNING: at arch/arm/kernel/smp_twd.c:345 > > twd_local_timer_of_register+0x7c/0x90() > > twd_local_timer_of_register failed (-6) > > Modules linked in: > > Backtrace: > > [<80011f14>] (dump_backtrace+0x0/0x10c) from [<8044dd30>] > > (dump_stack+0x18/0x1c) > > r7:805e9f58 r6:805ba84c r5:80539331 r4:00000159 > > [<8044dd18>] (dump_stack+0x0/0x1c) from [<80020fbc>] > > (warn_slowpath_common+0x54/0x6c) > > [<80020f68>] (warn_slowpath_common+0x0/0x6c) from [<80021078>] > > (warn_slowpath_fmt+0x38/0x40) > > r9:412fc09a r8:8fffffff r7:ffffffff r6:00000001 r5:80633b8c > > r4:80b32da8 > > [<80021040>] (warn_slowpath_fmt+0x0/0x40) from [<805ba84] > > (twd_local_timer_of_register+0x7c/0x90) > > r3:fffffffa r2:8053934b > > [<805ba7d0>] (twd_local_timer_of_register+0x0/0x90) from [<805c0bec>] > > (imx6q_timer_init+0x18/0x4c) > > r5:80633800 r4:8053b701 > > [<805c0bd4>] (imx6q_timer_init+0x0/0x4c) from [<805ba4e8>] > > (time_init+0x28/0x38) > > r5:80633800 r4:805dc0f4 > > [<805ba4c0>] (time_init+0x0/0x38) from [<805b6854>] > > (start_kernel+0x1a0/0x310) > > [<805b66b4>] (start_kernel+0x0/0x310) from [<10008044>] (0x10008044) > > r8:1000406a r7:805f3f8c r6:805dc0c4 r5:805f0518 r4:10c5387d > > ---[ end trace 1b75b31a2719ed1c ]--- > > > > > > I cannot reproduce on v4.2 + my platform... > > The warning has been removed in commit 5028090d1da1 (ARM: 8434/1: > Revert "7655/1: smp_twd: make twd_local_timer_of_register() no-op > for nosmp", 2015-09-14) sitting in linux-next. Oddly, that commit > doesn't remove the depends on SMP for the Kconfig. So it seems > that we can apply this patch and everyone is happy? We could also > drop the "if SMP" part of most of the platform selects if anyone > actually cares. heh, sorry about that. I forgot omap2plus_defconfig enables everything. I could refresh that patch if Russell is still okay taking a newer version of it. Russell ? -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: not available URL: