Re: [PATCH v2] spi: spi-imx: spi_imx_remove: do not disable disabled clocks

[Huang Shijie <b32955@xxxxxxxxxxxxx>]

于 2014年02月27日 17:16, Philippe De Muyter 写道:
> Currently, at module removal, one gets the following warnings:
> ------------[ cut here ]------------
> WARNING: at drivers/clk/clk.c:780 clk_disable+0x18/0x24()
> Modules linked in: spi_imx(-) [last unloaded: ev76c560]
> CPU: 1 PID: 16337 Comm: rmmod Tainted: G        W    3.10.17-80548-g90191eb-dirty #33
> [<80013b4c>] (unwind_backtrace+0x0/0xf8) from [<800115dc>] (show_stack+0x10/0x14)
> [<800115dc>] (show_stack+0x10/0x14) from [<800257b8>] (warn_slowpath_common+0x4c/0x68)
> [<800257b8>] (warn_slowpath_common+0x4c/0x68) from [<800257f0>] (warn_slowpath_null+0x1c/0x24)
> [<800257f0>] (warn_slowpath_null+0x1c/0x24) from [<803f60ec>] (clk_disable+0x18/0x24)
> [<803f60ec>] (clk_disable+0x18/0x24) from [<7f02c9cc>] (spi_imx_remove+0x54/0x9c [spi_imx])
> [<7f02c9cc>] (spi_imx_remove+0x54/0x9c [spi_imx]) from [<8025868c>] (platform_drv_remove+0x18/0x1c)
> [<8025868c>] (platform_drv_remove+0x18/0x1c) from [<80256f60>] (__device_release_driver+0x70/0xcc)
> [<80256f60>] (__device_release_driver+0x70/0xcc) from [<80257770>] (driver_detach+0xcc/0xd0)
> [<80257770>] (driver_detach+0xcc/0xd0) from [<80256d90>] (bus_remove_driver+0x7c/0xc0)
> [<80256d90>] (bus_remove_driver+0x7c/0xc0) from [<80068668>] (SyS_delete_module+0x144/0x1f8)
> [<80068668>] (SyS_delete_module+0x144/0x1f8) from [<8000e080>] (ret_fast_syscall+0x0/0x30)
> ---[ end trace 1f5df9ad54996300 ]---
> ------------[ cut here ]------------
> WARNING: at drivers/clk/clk.c:780 clk_disable+0x18/0x24()
> Modules linked in: spi_imx(-) [last unloaded: ev76c560]
> CPU: 1 PID: 16337 Comm: rmmod Tainted: G        W    3.10.17-80548-g90191eb-dirty #33
> [<80013b4c>] (unwind_backtrace+0x0/0xf8) from [<800115dc>] (show_stack+0x10/0x14)
> [<800115dc>] (show_stack+0x10/0x14) from [<800257b8>] (warn_slowpath_common+0x4c/0x68)
> [<800257b8>] (warn_slowpath_common+0x4c/0x68) from [<800257f0>] (warn_slowpath_null+0x1c/0x24)
> [<800257f0>] (warn_slowpath_null+0x1c/0x24) from [<803f60ec>] (clk_disable+0x18/0x24)
> [<803f60ec>] (clk_disable+0x18/0x24) from [<7f02c9e8>] (spi_imx_remove+0x70/0x9c [spi_imx])
> [<7f02c9e8>] (spi_imx_remove+0x70/0x9c [spi_imx]) from [<8025868c>] (platform_drv_remove+0x18/0x1c)
> [<8025868c>] (platform_drv_remove+0x18/0x1c) from [<80256f60>] (__device_release_driver+0x70/0xcc)
> [<80256f60>] (__device_release_driver+0x70/0xcc) from [<80257770>] (driver_detach+0xcc/0xd0)
> [<80257770>] (driver_detach+0xcc/0xd0) from [<80256d90>] (bus_remove_driver+0x7c/0xc0)
> [<80256d90>] (bus_remove_driver+0x7c/0xc0) from [<80068668>] (SyS_delete_module+0x144/0x1f8)
> [<80068668>] (SyS_delete_module+0x144/0x1f8) from [<8000e080>] (ret_fast_syscall+0x0/0x30)
> ---[ end trace 1f5df9ad54996301 ]---
>
> Since commit 9e556dcc55774c9a1032f32baa0e5cfafede8b70, "spi: spi-imx: only
> enable the clocks when we start to transfer a message", clocks are always
> disabled except when transmitting messages.  There is thus no need to
> disable them at module removal.
>
> Signed-off-by: Philippe De Muyter <phdm@xxxxxxxxx>
> Cc: Huang Shijie <b32955@xxxxxxxxxxxxx>
> Cc: Mark Brown <broonie@xxxxxxxxxx>
> Cc: Shawn Guo <shawn.guo@xxxxxxxxxx>
> ---
> Change since v1:
> keep the 'unprepare' part (Thanks Huang)
>  drivers/spi/spi-imx.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
> index a5474ef..47f15d9 100644
> --- a/drivers/spi/spi-imx.c
> +++ b/drivers/spi/spi-imx.c
> @@ -948,8 +948,8 @@ static int spi_imx_remove(struct platform_device *pdev)
>  	spi_bitbang_stop(&spi_imx->bitbang);
>  
>  	writel(0, spi_imx->base + MXC_CSPICTRL);
> -	clk_disable_unprepare(spi_imx->clk_ipg);
> -	clk_disable_unprepare(spi_imx->clk_per);
> +	clk_unprepare(spi_imx->clk_ipg);
> +	clk_unprepare(spi_imx->clk_per);
>  	spi_master_put(master);
>  
>  	return 0;
Acked-by: Huang Shijie <b32955@xxxxxxxxxxxxx>

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