From: u.kleine-koenig@pengutronix.de (Uwe Kleine-König)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] video: imxfb: Do not crash on reboot
Date: Tue, 9 Oct 2012 09:45:49 +0200 [thread overview]
Message-ID: <20121009074549.GG18531@pengutronix.de> (raw)
In-Reply-To: <1349703336-8105-1-git-send-email-fabio.estevam@freescale.com>
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-K?nig |
Industrial Linux Solutions | http://www.pengutronix.de/ |
prev parent reply other threads:[~2012-10-09 7:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-08 13:35 [PATCH] video: imxfb: Do not crash on reboot Fabio Estevam
2012-10-08 20:52 ` Sascha Hauer
2012-10-09 7:45 ` Uwe Kleine-König [this message]
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