fec: warning found by dma debug

fec: warning found by dma debug

[Christian Gmeiner]

[   17.946189] ------------[ cut here ]------------
[   17.950848] WARNING: CPU: 0 PID: 3 at lib/dma-debug.c:1093
check_unmap+0x858/0xa10()
[   17.958674] fec 2188000.ethernet: DMA-API: device driver tries to
free DMA memory it has not allocated [device
address=0x0000000000000000] [size=34 bytes]
[   17.972564] Modules linked in: etnaviv(C) imx_ipuv3_crtc imx_hdmi
imxdrm drm_kms_helper drm
[   17.981086] CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G        WC
 3.19.0-rc4+ #31
[   17.988893] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[   17.995488] Backtrace:
[   17.997982] [<c00135f0>] (dump_backtrace) from [<c0013948>]
(show_stack+0x20/0x24)
[   18.005609]  r6:c0883d40 r5:ffffffff r4:00000000 r3:dc8cb100
[   18.011369] [<c0013928>] (show_stack) from [<c06a2ac0>]
(dump_stack+0x78/0xc4)
[   18.018683] [<c06a2a48>] (dump_stack) from [<c002c0a4>]
(warn_slowpath_common+0x88/0xc4)
[   18.026845]  r5:00000445 r4:e5205c80
[   18.030479] [<c002c01c>] (warn_slowpath_common) from [<c002c19c>]
(warn_slowpath_fmt+0x40/0x48)
[   18.039231]  r8:00000000 r7:00000000 r6:00000022 r5:c0af9e18 r4:00000000
[   18.046066] [<c002c160>] (warn_slowpath_fmt) from [<c038dc30>]
(check_unmap+0x858/0xa10)
[   18.054216]  r3:c089bb90 r2:c0884270
[   18.057846] [<c038d3d8>] (check_unmap) from [<c038e0c4>]
(debug_dma_unmap_page+0x80/0x88)
[   18.066087]  r10:e38890c0 r9:00000000 r8:00000001 r7:00000001
r6:e53f8850 r5:00000000
[   18.074069]  r4:00000022
[   18.076647] [<c038e044>] (debug_dma_unmap_page) from [<c045e368>]
(fec_enet_rx_napi+0x7c0/0xb94)
[   18.085494]  r8:00001400 r7:e795c780 r6:e389a0c0 r5:00000000 r4:00000000
[   18.092349] [<c045dba8>] (fec_enet_rx_napi) from [<c053f14c>]
(net_rx_action+0x130/0x568)
[   18.100537]  r10:c0aefa80 r9:ffff91be r8:e5205e48 r7:00000040
r6:0000012c r5:00000001
[   18.108537]  r4:e38897b0
[   18.111113] [<c053f01c>] (net_rx_action) from [<c0030768>]
(__do_softirq+0x11c/0x794)
[   18.118999]  r10:00000100 r9:c0053c58 r8:00000004 r7:c0b5ddac
r6:00000008 r5:c0af208c
[   18.127008]  r4:00000003
[   18.129573] [<c003064c>] (__do_softirq) from [<c0030e20>]
(run_ksoftirqd+0x40/0x6c)
[   18.137291]  r10:00000000 r9:c0053c58 r8:c0b017cc r7:00000000
r6:0000103c r5:e5157a00
[   18.145298]  r4:00000001
[   18.147878] [<c0030de0>] (run_ksoftirqd) from [<c0053de4>]
(smpboot_thread_fn+0x1b0/0x354)
[   18.156208] [<c0053c34>] (smpboot_thread_fn) from [<c004f114>]
(kthread+0x104/0x128)
[   18.164011]  r10:00000000 r9:00000000 r8:00000000 r7:c0053c34
r6:e5157a00 r5:00000000
[   18.172006]  r4:e5157800 r3:00000005
[   18.175651] [<c004f010>] (kthread) from [<c000fc08>]
(ret_from_fork+0x14/0x2c)
[   18.182937]  r7:00000000 r6:00000000 r5:c004f010 r4:e5157800
[   18.188680] ---[ end trace dcf0152c9771f20a ]---

--
Christian Gmeiner, MSc

https://soundcloud.com/christian-gmeiner

Re: fec: warning found by dma debug

[Fabio Estevam]

Thanks for the report, Christian

Adding Andy and Russell on Cc.

On Fri, Jan 16, 2015 at 9:05 AM, Christian Gmeiner
<christian.gmeiner@gmail.com> wrote:
> [   17.946189] ------------[ cut here ]------------
> [   17.950848] WARNING: CPU: 0 PID: 3 at lib/dma-debug.c:1093
> check_unmap+0x858/0xa10()
> [   17.958674] fec 2188000.ethernet: DMA-API: device driver tries to
> free DMA memory it has not allocated [device
> address=0x0000000000000000] [size=34 bytes]
> [   17.972564] Modules linked in: etnaviv(C) imx_ipuv3_crtc imx_hdmi
> imxdrm drm_kms_helper drm
> [   17.981086] CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G        WC
>  3.19.0-rc4+ #31
> [   17.988893] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> [   17.995488] Backtrace:
> [   17.997982] [<c00135f0>] (dump_backtrace) from [<c0013948>]
> (show_stack+0x20/0x24)
> [   18.005609]  r6:c0883d40 r5:ffffffff r4:00000000 r3:dc8cb100
> [   18.011369] [<c0013928>] (show_stack) from [<c06a2ac0>]
> (dump_stack+0x78/0xc4)
> [   18.018683] [<c06a2a48>] (dump_stack) from [<c002c0a4>]
> (warn_slowpath_common+0x88/0xc4)
> [   18.026845]  r5:00000445 r4:e5205c80
> [   18.030479] [<c002c01c>] (warn_slowpath_common) from [<c002c19c>]
> (warn_slowpath_fmt+0x40/0x48)
> [   18.039231]  r8:00000000 r7:00000000 r6:00000022 r5:c0af9e18 r4:00000000
> [   18.046066] [<c002c160>] (warn_slowpath_fmt) from [<c038dc30>]
> (check_unmap+0x858/0xa10)
> [   18.054216]  r3:c089bb90 r2:c0884270
> [   18.057846] [<c038d3d8>] (check_unmap) from [<c038e0c4>]
> (debug_dma_unmap_page+0x80/0x88)
> [   18.066087]  r10:e38890c0 r9:00000000 r8:00000001 r7:00000001
> r6:e53f8850 r5:00000000
> [   18.074069]  r4:00000022
> [   18.076647] [<c038e044>] (debug_dma_unmap_page) from [<c045e368>]
> (fec_enet_rx_napi+0x7c0/0xb94)
> [   18.085494]  r8:00001400 r7:e795c780 r6:e389a0c0 r5:00000000 r4:00000000
> [   18.092349] [<c045dba8>] (fec_enet_rx_napi) from [<c053f14c>]
> (net_rx_action+0x130/0x568)
> [   18.100537]  r10:c0aefa80 r9:ffff91be r8:e5205e48 r7:00000040
> r6:0000012c r5:00000001
> [   18.108537]  r4:e38897b0
> [   18.111113] [<c053f01c>] (net_rx_action) from [<c0030768>]
> (__do_softirq+0x11c/0x794)
> [   18.118999]  r10:00000100 r9:c0053c58 r8:00000004 r7:c0b5ddac
> r6:00000008 r5:c0af208c
> [   18.127008]  r4:00000003
> [   18.129573] [<c003064c>] (__do_softirq) from [<c0030e20>]
> (run_ksoftirqd+0x40/0x6c)
> [   18.137291]  r10:00000000 r9:c0053c58 r8:c0b017cc r7:00000000
> r6:0000103c r5:e5157a00
> [   18.145298]  r4:00000001
> [   18.147878] [<c0030de0>] (run_ksoftirqd) from [<c0053de4>]
> (smpboot_thread_fn+0x1b0/0x354)
> [   18.156208] [<c0053c34>] (smpboot_thread_fn) from [<c004f114>]
> (kthread+0x104/0x128)
> [   18.164011]  r10:00000000 r9:00000000 r8:00000000 r7:c0053c34
> r6:e5157a00 r5:00000000
> [   18.172006]  r4:e5157800 r3:00000005
> [   18.175651] [<c004f010>] (kthread) from [<c000fc08>]
> (ret_from_fork+0x14/0x2c)
> [   18.182937]  r7:00000000 r6:00000000 r5:c004f010 r4:e5157800
> [   18.188680] ---[ end trace dcf0152c9771f20a ]---
>
> --
> Christian Gmeiner, MSc
>
> https://soundcloud.com/christian-gmeiner
> --
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Re: fec: warning found by dma debug

[Russell King - ARM Linux]

On Fri, Jan 16, 2015 at 09:32:20AM -0200, Fabio Estevam wrote:
> Thanks for the report, Christian
> 
> Adding Andy and Russell on Cc.

Yes, this is highly possible.  My patch set which addressed all sorts
of issues like this is now a year old, and I gave up with trying to
get it merged - it became far too difficult to constantly update the
patch set.

I think Marek was going to look at taking over the patch set, but I've
heard nothing from him.  The patch set can be found at:

  git://ftp.arm.linux.org.uk/~rmk/linux-arm.git fec-testing

but beware: not all of it is meant to be merged.  That branch represents
all patches I tried to solve various problems and improve performance
and correctness (from the ARM architecture point of view).  I did a lot
of work to evaluate the effect of each individual patch, and tried to
only include patches which did not cause a regression.  From what I
remember, every patch (apart from the branch head) from 7e291d514886
(net:fec: unsorted hacks) onwards was not well proven - but that was
all done before the driver ended up with TSO support.

Post TSO support, patches with "net: fec:" (note the space) /were/ good
to go, but then the multiple-queue support got merged which completely
screwed the patch set again.

So, I just totally gave up.  Sorry.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.