Messages in this thread | | | Date | Tue, 9 Oct 2012 09:45:49 +0200 | From | Uwe Kleine-König <> | Subject | Re: [PATCH] video: imxfb: Do not crash on reboot |
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On Mon, Oct 08, 2012 at 10:35:36AM -0300, Fabio Estevam wrote: > Issuing a "reboot" command after the LCD times out causes the following > warnings: > > Requesting system reboot > ------------[ cut here ]------------ > WARNING: at drivers/clk/clk.c:471 clk_disable+0x24/0x50() > Modules linked in: > [<c001ad90>] (unwind_backtrace+0x0/0xf4) from [<c0025aac>] (warn_slowpath_common+0x48/0x60) > [<c0025aac>] (warn_slowpath_common+0x48/0x60) from [<c0025ae0>] (warn_slowpath_null+0x1c/0x24) > [<c0025ae0>] (warn_slowpath_null+0x1c/0x24) from [<c03960a0>] (clk_disable+0x24/0x50) > [<c03960a0>] (clk_disable+0x24/0x50) from [<c02695a0>] (imxfb_disable_controller+0x48/0x7c) > [<c02695a0>] (imxfb_disable_controller+0x48/0x7c) from [<c029d838>] (platform_drv_shutdown+0x18/0x1c) > [<c029d838>] (platform_drv_shutdown+0x18/0x1c) from [<c02990fc>] (device_shutdown+0x48/0x14c) > [<c02990fc>] (device_shutdown+0x48/0x14c) from [<c003d09c>] (kernel_restart_prepare+0x2c/0x3c) > [<c003d09c>] (kernel_restart_prepare+0x2c/0x3c) from [<c003d0e4>] (kernel_restart+0xc/0x48) > [<c003d0e4>] (kernel_restart+0xc/0x48) from [<c003d1e8>] (sys_reboot+0xc0/0x1bc) > [<c003d1e8>] (sys_reboot+0xc0/0x1bc) from [<c0014ca0>] (ret_fast_syscall+0x0/0x2c) > ---[ end trace da6b502ca79c854f ]--- > ------------[ cut here ]------------ > WARNING: at drivers/clk/clk.c:380 clk_unprepare+0x1c/0x2c() > Modules linked in: > [<c001ad90>] (unwind_backtrace+0x0/0xf4) from [<c0025aac>] (warn_slowpath_common+0x48/0x60) > [<c0025aac>] (warn_slowpath_common+0x48/0x60) from [<c0025ae0>] (warn_slowpath_null+0x1c/0x24) > [<c0025ae0>] (warn_slowpath_null+0x1c/0x24) from [<c0396338>] (clk_unprepare+0x1c/0x2c) > [<c0396338>] (clk_unprepare+0x1c/0x2c) from [<c02695a8>] (imxfb_disable_controller+0x50/0x7c) > [<c02695a8>] (imxfb_disable_controller+0x50/0x7c) from [<c029d838>] (platform_drv_shutdown+0x18/0x1c) > [<c029d838>] (platform_drv_shutdown+0x18/0x1c) from [<c02990fc>] (device_shutdown+0x48/0x14c) > [<c02990fc>] (device_shutdown+0x48/0x14c) from [<c003d09c>] (kernel_restart_prepare+0x2c/0x3c) > [<c003d09c>] (kernel_restart_prepare+0x2c/0x3c) from [<c003d0e4>] (kernel_restart+0xc/0x48) > [<c003d0e4>] (kernel_restart+0xc/0x48) from [<c003d1e8>] (sys_reboot+0xc0/0x1bc) > [<c003d1e8>] (sys_reboot+0xc0/0x1bc) from [<c0014ca0>] (ret_fast_syscall+0x0/0x2c) > ---[ end trace da6b502ca79c8550 ]--- > ------------[ cut here ]------------ > > This happens because "reboot" triggers imxfb_shutdown(), which calls > imxfb_disable_controller with the clocks already disabled. > > To prevent this, add a clock enabled status so that we can check if the clocks > are enabled before disabling them. > > Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> > --- > drivers/video/imxfb.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/drivers/video/imxfb.c b/drivers/video/imxfb.c > index f3363b2..6acf98a 100644 > --- a/drivers/video/imxfb.c > +++ b/drivers/video/imxfb.c > @@ -134,6 +134,7 @@ struct imxfb_info { > struct clk *clk_ipg; > struct clk *clk_ahb; > struct clk *clk_per; > + int enabled; I didn't really know the driver, but I wonder if the name "enabled" is a tad too generic. Maybe better "clks_enabled"?
Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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