Hi Fabio,
On Sun, 2018-06-24 at 19:40 -0300, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@xxxxxxx>
>
> Russell King reported:
>
> "When removing and reloading the etnaviv module, the following splat
> occurs:
>
> sysfs: cannot create duplicate filename '/devices/platform/etnaviv'
> CPU: 0 PID: 1471 Comm: modprobe Not tainted 4.17.0+ #1608
> Hardware name: Marvell Dove (Cubox)
> Backtrace:
> [<c00157d4>] (dump_backtrace) from [<c0015b8c>] (show_stack+0x18/0x1c)
> r6:ef033e38 r5:ee07b340 r4:edb9d000 r3:00000000
> [<c0015b74>] (show_stack) from [<c0620784>] (dump_stack+0x20/0x28)
> [<c0620764>] (dump_stack) from [<c01bcd24>] (sysfs_warn_dup+0x5c/0x70)
> [<c01bccc8>] (sysfs_warn_dup) from [<c01bce14>] (sysfs_create_dir_ns+0x90/0x98)
> ..."
>
> Commit 246774d17fc0 ("drm/etnaviv: remove the need for a gpu-subsystem
> DT node") introduced DRM registration via
> platform_device_register_simple(), but missed to call
> platform_device_unregister() inside etnaviv_exit().
>
> Fix the problem by calling platform_device_unregister() inside
> etnaviv_exit(). While at it, also rearrange the function calls
> in the exit path to make them happen in the opposite order of
> registration.
>
> Tested on a imx6-sabresd board.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Fixes: 246774d17fc0 ("drm/etnaviv: remove the need for a gpu-subsystem DT node")
> Reported-by: Russell King <linux@xxxxxxxxxxxxxxx>
> Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx>
> ---
> Changes since v1:
> - Make the exit path symmetrical to the init path by calling
> platform_device_unregister() inside for_each_compatible_node()
>
> drivers/gpu/drm/etnaviv/etnaviv_drv.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> index e5013a9..626ad8b 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> @@ -631,6 +631,8 @@ static struct platform_driver etnaviv_platform_driver = {
> },
> };
>
> +static struct platform_device *etnaviv_drm;
> +
> static int __init etnaviv_init(void)
> {
> int ret;
> @@ -654,7 +656,8 @@ static int __init etnaviv_init(void)
> if (!of_device_is_available(np))
> continue;
>
> - platform_device_register_simple("etnaviv", -1, NULL, 0);
> + etnaviv_drm = platform_device_register_simple("etnaviv", -1,
> + NULL, 0);
If there are multiple vivante,gc device nodes, this overwrites
etnaviv_drm with each additional device after the first one.
Also, it would be better to store NULL instead of the error value.
> of_node_put(np);
> break;
> }
> @@ -665,8 +668,19 @@ module_init(etnaviv_init);
>
> static void __exit etnaviv_exit(void)
> {
> - platform_driver_unregister(&etnaviv_gpu_driver);
> + struct device_node *np;
> +
> + for_each_compatible_node(np, NULL, "vivante,gc") {
> + if (!of_device_is_available(np))
> + continue;
> +
> + platform_device_unregister(etnaviv_drm);
If there are multiple vivante,gc nodes, this will try to unregister the
last device multiple times. Also, this will break if the pointer
contains an error value.
> + of_node_put(np);
> + break;
> + }
> +
> platform_driver_unregister(&etnaviv_platform_driver);
> + platform_driver_unregister(&etnaviv_gpu_driver);
> }
> module_exit(etnaviv_exit);
>
regards
Philipp
