Message ID | 1452854061-30370-1-git-send-email-alexandre.belloni@free-electrons.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Le 15/01/2016 11:34, Alexandre Belloni a écrit : > clockevents_exchange_device is calling clockevents_shutdown() on the new > clockenvents device but it may have never been enabled in the first place. > This results in the tcb clock being disabled without being enabled first: > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:680 clk_disable+0x28/0x34() > Modules linked in: > CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.0+ #6 > Hardware name: Atmel AT91SAM9 > [<c000f2b8>] (unwind_backtrace) from [<c000d01c>] (show_stack+0x10/0x14) > [<c000d01c>] (show_stack) from [<c00172f0>] (warn_slowpath_common+0x78/0xa0) > [<c00172f0>] (warn_slowpath_common) from [<c00173a8>] (warn_slowpath_null+0x18/0x20) > [<c00173a8>] (warn_slowpath_null) from [<c0361528>] (clk_disable+0x28/0x34) > [<c0361528>] (clk_disable) from [<c034d560>] (tc_shutdown+0x38/0x4c) > [<c034d560>] (tc_shutdown) from [<c0059ad4>] (clockevents_switch_state+0x38/0x6c) > [<c0059ad4>] (clockevents_switch_state) from [<c0059b18>] (clockevents_shutdown+0x10/0x24) > [<c0059b18>] (clockevents_shutdown) from [<c005a458>] (tick_check_new_device+0x84/0xac) > [<c005a458>] (tick_check_new_device) from [<c0059660>] (clockevents_register_device+0x7c/0x108) > [<c0059660>] (clockevents_register_device) from [<c06b5a68>] (tcb_clksrc_init+0x390/0x3e8) > [<c06b5a68>] (tcb_clksrc_init) from [<c00097cc>] (do_one_initcall+0x114/0x1d4) > [<c00097cc>] (do_one_initcall) from [<c069bd54>] (kernel_init_freeable+0xfc/0x1b8) > [<c069bd54>] (kernel_init_freeable) from [<c04c3818>] (kernel_init+0x8/0xe0) > [<c04c3818>] (kernel_init) from [<c000a410>] (ret_from_fork+0x14/0x24) > ---[ end trace 0000000000000001 ]--- > > Check what state we were in before trying to disable the clock. > > Fixes: cf4541c101ea ("clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface") > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Thanks! > --- > drivers/clocksource/tcb_clksrc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c > index 6ee91401918e..4da2af9694a2 100644 > --- a/drivers/clocksource/tcb_clksrc.c > +++ b/drivers/clocksource/tcb_clksrc.c > @@ -98,7 +98,8 @@ static int tc_shutdown(struct clock_event_device *d) > > __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR)); > __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); > - clk_disable(tcd->clk); > + if (!clockevent_state_detached(d)) > + clk_disable(tcd->clk); > > return 0; > } >
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c index 6ee91401918e..4da2af9694a2 100644 --- a/drivers/clocksource/tcb_clksrc.c +++ b/drivers/clocksource/tcb_clksrc.c @@ -98,7 +98,8 @@ static int tc_shutdown(struct clock_event_device *d) __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR)); __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); - clk_disable(tcd->clk); + if (!clockevent_state_detached(d)) + clk_disable(tcd->clk); return 0; }
clockevents_exchange_device is calling clockevents_shutdown() on the new clockenvents device but it may have never been enabled in the first place. This results in the tcb clock being disabled without being enabled first: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:680 clk_disable+0x28/0x34() Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.0+ #6 Hardware name: Atmel AT91SAM9 [<c000f2b8>] (unwind_backtrace) from [<c000d01c>] (show_stack+0x10/0x14) [<c000d01c>] (show_stack) from [<c00172f0>] (warn_slowpath_common+0x78/0xa0) [<c00172f0>] (warn_slowpath_common) from [<c00173a8>] (warn_slowpath_null+0x18/0x20) [<c00173a8>] (warn_slowpath_null) from [<c0361528>] (clk_disable+0x28/0x34) [<c0361528>] (clk_disable) from [<c034d560>] (tc_shutdown+0x38/0x4c) [<c034d560>] (tc_shutdown) from [<c0059ad4>] (clockevents_switch_state+0x38/0x6c) [<c0059ad4>] (clockevents_switch_state) from [<c0059b18>] (clockevents_shutdown+0x10/0x24) [<c0059b18>] (clockevents_shutdown) from [<c005a458>] (tick_check_new_device+0x84/0xac) [<c005a458>] (tick_check_new_device) from [<c0059660>] (clockevents_register_device+0x7c/0x108) [<c0059660>] (clockevents_register_device) from [<c06b5a68>] (tcb_clksrc_init+0x390/0x3e8) [<c06b5a68>] (tcb_clksrc_init) from [<c00097cc>] (do_one_initcall+0x114/0x1d4) [<c00097cc>] (do_one_initcall) from [<c069bd54>] (kernel_init_freeable+0xfc/0x1b8) [<c069bd54>] (kernel_init_freeable) from [<c04c3818>] (kernel_init+0x8/0xe0) [<c04c3818>] (kernel_init) from [<c000a410>] (ret_from_fork+0x14/0x24) ---[ end trace 0000000000000001 ]--- Check what state we were in before trying to disable the clock. Fixes: cf4541c101ea ("clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface") Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> --- drivers/clocksource/tcb_clksrc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)