Re: [PATCH] dmaengine: qcom_hidma: remove useless debugfs file removal

From: Vinod Koul
Date: Wed Oct 19 2016 - 10:48:06 EST


On Thu, Oct 06, 2016 at 06:21:29PM -0400, Sinan Kaya wrote:
> Since 'commit acc29fb8f792 ("debugfs: ->d_parent is never NULL or
> negative")', HIDMA object removal is no longer working. This is due to
> redundant debugfs remove call in hidma_debug_uninit.
>
> debugfs_remove_recursive(dmadev->debugfs);
> debugfs_remove_recursive(dmadev->stats);
>
> The first remove is for the directory. Second remove is for the file under
> the directory. The directory remove makes file remove invalid.
>
> Unable to handle kernel NULL pointer dereference at virtual address
>
> [<ffff00000889f480>] down_write+0x18/0x68
> [<ffff00000831c220>] debugfs_remove_recursive+0x50/0x1c0
> [<ffff00000848e0a8>] hidma_debug_uninit+0x20/0x30
> [<ffff00000848c5d8>] hidma_remove+0x48/0x98
> [<ffff000008511b6c>] platform_drv_remove+0x24/0x68
> [<ffff00000850fac8>] __device_release_driver+0x80/0x118
> [<ffff00000850fb84>] device_release_driver+0x24/0x38
> [<ffff00000850e928>] unbind_store+0xe8/0x110
> [<ffff00000850dd30>] drv_attr_store+0x20/0x30
> [<ffff000008253a48>] sysfs_kf_write+0x48/0x58
> [<ffff000008252dd8>] kernfs_fop_write+0xb0/0x1d8
> [<ffff0000081dab3c>] __vfs_write+0x1c/0x110
> [<ffff0000081db940>] vfs_write+0xa0/0x1b8
> [<ffff0000081dcd34>] SyS_write+0x44/0xa0
> [<ffff000008082ef0>] el0_svc_naked+0x24/0x28
>
> Removing the second line.

Applied, thanks

--
~Vinod