From: Vinod Koul <vinod.koul@intel.com>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Dan Williams <dan.j.williams@intel.com>,
linaro-kernel@lists.linaro.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dmaengine: device must have at least one channel
Date: Mon, 22 Aug 2016 11:49:30 +0530 [thread overview]
Message-ID: <20160822061930.GJ2890@localhost> (raw)
In-Reply-To: <4a6e2283fb7736c33fb733c310314d7bc135cd6d.1469654853.git.viresh.kumar@linaro.org>
On Wed, Jul 27, 2016 at 02:32:58PM -0700, Viresh Kumar wrote:
> The DMA device can't be registered if it doesn't have any channels
> registered at all. Moreover, it leads to memory leak and is reported by
> kmemleak as (on 3.10 kernel, and same shall happen on mainline):
>
> unreferenced object 0xffffffc09e597240 (size 64):
> comm "swapper/0", pid 1, jiffies 4294877736 (age 7060.280s)
> hex dump (first 32 bytes):
> 00 00 00 00 c0 ff ff ff 30 00 00 ff 00 00 00 ff ........0.......
> 00 00 00 ff 00 00 00 ff 00 00 00 ff 00 00 00 ff ................
> backtrace:
> [<ffffffc0003079ec>] create_object+0x148/0x2a0
> [<ffffffc000cc150c>] kmemleak_alloc+0x80/0xbc
> [<ffffffc000303a7c>] kmem_cache_alloc_trace+0x120/0x1ac
> [<ffffffc00054771c>] dma_async_device_register+0x160/0x46c
> [<ffffffc000548958>] foo_probe+0x1a0/0x264
> [<ffffffc0005d6658>] platform_drv_probe+0x14/0x20
> [<ffffffc0005d50cc>] driver_probe_device+0x160/0x374
> [<ffffffc0005d538c>] __driver_attach+0x60/0x90
> [<ffffffc0005d3e78>] bus_for_each_dev+0x7c/0xb0
> [<ffffffc0005d4a0c>] driver_attach+0x1c/0x28
> [<ffffffc0005d459c>] bus_add_driver+0x124/0x248
> [<ffffffc0005d59cc>] driver_register+0x90/0x110
> [<ffffffc0005d6bf4>] platform_driver_register+0x58/0x64
> [<ffffffc00142a70c>] foo_driver_init+0x10/0x1c
> [<ffffffc000200878>] do_one_initcall+0xac/0x148
> [<ffffffc00140096c>] kernel_init_freeable+0x1a0/0x258
>
> Return -ENODEV from dma_async_device_register() on such a case.
Applied, thanks
--
~Vinod
prev parent reply other threads:[~2016-08-22 6:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-27 21:32 [PATCH] dmaengine: device must have at least one channel Viresh Kumar
2016-07-28 3:48 ` Vinod Koul
2016-07-28 4:48 ` Viresh Kumar
2016-08-03 19:34 ` Greg Kroah-Hartman
2016-08-05 16:30 ` Viresh Kumar
2016-08-08 8:17 ` Vinod Koul
2016-08-08 15:24 ` Viresh Kumar
2016-08-08 17:06 ` Greg Kroah-Hartman
2016-08-08 17:08 ` Viresh Kumar
2016-08-22 6:19 ` Vinod Koul [this message]
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