* [dmaengine] Cyclic DMA regression.
@ 2012-04-03 10:17 javier Martin
2012-04-05 6:08 ` Vinod Koul
0 siblings, 1 reply; 4+ messages in thread
From: javier Martin @ 2012-04-03 10:17 UTC (permalink / raw)
To: linux-kernel; +Cc: Russell King, Vinod Koul
The following BUG has been found trying an 'aplay' with a
Visstrim_SM10 board in linux-3.4-rc1:
aplay /usr/share/sounds/linphone/hello16000.wav
Playing WAVE '/usr/share/sounds/linphone/hello16000.wav' : Signed 16
bit Little Endian, Rate 16000 Hz, Mono
------------[ cut here ]------------
kernel BUG at drivers/dma/dmaengine.h:53!
Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 Not tainted (3.4.0-rc1 #18)
PC is at imxdma_tasklet+0x118/0x140
LR is at imxdma_tasklet+0x38/0x140
pc : [<c022af9c>] lr : [<c022aebc>] psr: 60000013
sp : c049fed8 ip : c31974a4 fp : c04d85a0
r10: c04d85b8 r9 : 00000102 r8 : 00000001
r7 : c3018000 r6 : c30181ac r5 : c3018160 r4 : c3343f60
r3 : 00000000 r2 : 00000000 r1 : 0000001d r0 : c31974b8
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: 0005317f Table: a3330000 DAC: 00000017
Process swapper (pid: 0, stack limit = 0xc049e270)
Stack: (0xc049fed8 to 0xc04a0000)
fec0: 00000000 c04ab758
fee0: 00000000 00000018 00000001 c0028a14 c049e000 00000006 c049e000 c0028fdc
ff00: c04afeb8 00000000 0000000a 00000000 41069264 c049e000 c04c3c10 00000000
ff20: c049ff94 c04d3940 41069264 c04a6000 00000000 c0029330 00000021 c0015520
ff40: c049ff60 0000ffff c04d3c48 c00086f0 c0015738 60000013 ffffffff c0362200
ff60: 00000000 0005317f 0005217f 60000013 c049e000 c04d39c8 c04a8de0 00000001
ff80: c04d3940 41069264 c04a6000 00000000 600000d3 c049ffa8 c001572c c0015738
ffa0: 60000013 ffffffff c049e000 c0015cdc c04a6390 00000000 c0498684 c047f824
ffc0: 00000000 00000000 c047f360 00000000 00000000 c0498684 00000000 00053175
ffe0: c04a601c c0498680 c04a8dd4 a0004000 a04973e8 a0008040 00000000 00000000
[<c022af9c>] (imxdma_tasklet+0x118/0x140) from [<c0028a14>]
(tasklet_action+0x70/0xd8)
[<c0028a14>] (tasklet_action+0x70/0xd8) from [<c0028fdc>]
(__do_softirq+0xf0/0x240)
[<c0028fdc>] (__do_softirq+0xf0/0x240) from [<c0029330>] (irq_exit+0x88/0x9c)
[<c0029330>] (irq_exit+0x88/0x9c) from [<c0015520>] (handle_IRQ+0x34/0x84)
[<c0015520>] (handle_IRQ+0x34/0x84) from [<c00086f0>]
(avic_handle_irq+0x30/0x50)
[<c00086f0>] (avic_handle_irq+0x30/0x50) from [<c0362200>] (__irq_svc+0x40/0x6c)
Exception stack(0xc049ff60 to 0xc049ffa8)
ff60: 00000000 0005317f 0005217f 60000013 c049e000 c04d39c8 c04a8de0 00000001
ff80: c04d3940 41069264 c04a6000 00000000 600000d3 c049ffa8 c001572c c0015738
ffa0: 60000013 ffffffff
[<c0362200>] (__irq_svc+0x40/0x6c) from [<c0015738>] (default_idle+0x38/0x40)
[<c0015738>] (default_idle+0x38/0x40) from [<c0015cdc>] (cpu_idle+0x9c/0xc4)
[<c0015cdc>] (cpu_idle+0x9c/0xc4) from [<c047f824>] (start_kernel+0x230/0x2a4)
Code: e3a03000 e595404c e5c530c0 eaffffd7 (e7f001f2)
---[ end trace 5b6e58d2f7425625 ]---
The issue is that all DMA cyclic users call "dmaengine_submit" just
once [1], so only one descriptor is used and this descriptor is just
looped until "dmaengine_terminateall" is called.
It seems this BUG affects every use of a DMA cyclic transfer in the kernel.
The implication of this is that the cookie of this descriptor is
always 0 when "dma_cookie_complete" is called.
I've temporally solved the problem in my local tree with this (dirty) patch:
---
diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h
index 17f983a..266e8ff 100644
--- a/drivers/dma/dmaengine.h
+++ b/drivers/dma/dmaengine.h
@@ -52,7 +52,7 @@ static inline void dma_cookie_complete(struct
dma_async_tx_descriptor *tx)
{
BUG_ON(tx->cookie < DMA_MIN_COOKIE);
tx->chan->completed_cookie = tx->cookie;
- tx->cookie = 0;
+// tx->cookie = 0;
}
/**
---
But I guess we need something cleaner here.
Regards.
[1] http://lxr.linux.no/#linux+v3.3.1/sound/soc/imx/imx-pcm-dma-mx2.c#L208
--
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [dmaengine] Cyclic DMA regression.
2012-04-03 10:17 [dmaengine] Cyclic DMA regression javier Martin
@ 2012-04-05 6:08 ` Vinod Koul
2012-04-09 7:09 ` javier Martin
0 siblings, 1 reply; 4+ messages in thread
From: Vinod Koul @ 2012-04-05 6:08 UTC (permalink / raw)
To: javier Martin; +Cc: linux-kernel, Russell King, Sascha Hauer
On Tue, 2012-04-03 at 12:17 +0200, javier Martin wrote:
> The following BUG has been found trying an 'aplay' with a
> Visstrim_SM10 board in linux-3.4-rc1:
>
> aplay /usr/share/sounds/linphone/hello16000.wav
> Playing WAVE '/usr/share/sounds/linphone/hello16000.wav' : Signed 16
> bit Little Endian, Rate 16000 Hz, Mono
> ------------[ cut here ]------------
> kernel BUG at drivers/dma/dmaengine.h:53!
> Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
> Modules linked in:
> CPU: 0 Not tainted (3.4.0-rc1 #18)
> PC is at imxdma_tasklet+0x118/0x140
> LR is at imxdma_tasklet+0x38/0x140
> pc : [<c022af9c>] lr : [<c022aebc>] psr: 60000013
> sp : c049fed8 ip : c31974a4 fp : c04d85a0
> r10: c04d85b8 r9 : 00000102 r8 : 00000001
> r7 : c3018000 r6 : c30181ac r5 : c3018160 r4 : c3343f60
> r3 : 00000000 r2 : 00000000 r1 : 0000001d r0 : c31974b8
> Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
> Control: 0005317f Table: a3330000 DAC: 00000017
> Process swapper (pid: 0, stack limit = 0xc049e270)
> Stack: (0xc049fed8 to 0xc04a0000)
> fec0: 00000000 c04ab758
> fee0: 00000000 00000018 00000001 c0028a14 c049e000 00000006 c049e000 c0028fdc
> ff00: c04afeb8 00000000 0000000a 00000000 41069264 c049e000 c04c3c10 00000000
> ff20: c049ff94 c04d3940 41069264 c04a6000 00000000 c0029330 00000021 c0015520
> ff40: c049ff60 0000ffff c04d3c48 c00086f0 c0015738 60000013 ffffffff c0362200
> ff60: 00000000 0005317f 0005217f 60000013 c049e000 c04d39c8 c04a8de0 00000001
> ff80: c04d3940 41069264 c04a6000 00000000 600000d3 c049ffa8 c001572c c0015738
> ffa0: 60000013 ffffffff c049e000 c0015cdc c04a6390 00000000 c0498684 c047f824
> ffc0: 00000000 00000000 c047f360 00000000 00000000 c0498684 00000000 00053175
> ffe0: c04a601c c0498680 c04a8dd4 a0004000 a04973e8 a0008040 00000000 00000000
> [<c022af9c>] (imxdma_tasklet+0x118/0x140) from [<c0028a14>]
> (tasklet_action+0x70/0xd8)
> [<c0028a14>] (tasklet_action+0x70/0xd8) from [<c0028fdc>]
> (__do_softirq+0xf0/0x240)
> [<c0028fdc>] (__do_softirq+0xf0/0x240) from [<c0029330>] (irq_exit+0x88/0x9c)
> [<c0029330>] (irq_exit+0x88/0x9c) from [<c0015520>] (handle_IRQ+0x34/0x84)
> [<c0015520>] (handle_IRQ+0x34/0x84) from [<c00086f0>]
> (avic_handle_irq+0x30/0x50)
> [<c00086f0>] (avic_handle_irq+0x30/0x50) from [<c0362200>] (__irq_svc+0x40/0x6c)
> Exception stack(0xc049ff60 to 0xc049ffa8)
> ff60: 00000000 0005317f 0005217f 60000013 c049e000 c04d39c8 c04a8de0 00000001
> ff80: c04d3940 41069264 c04a6000 00000000 600000d3 c049ffa8 c001572c c0015738
> ffa0: 60000013 ffffffff
> [<c0362200>] (__irq_svc+0x40/0x6c) from [<c0015738>] (default_idle+0x38/0x40)
> [<c0015738>] (default_idle+0x38/0x40) from [<c0015cdc>] (cpu_idle+0x9c/0xc4)
> [<c0015cdc>] (cpu_idle+0x9c/0xc4) from [<c047f824>] (start_kernel+0x230/0x2a4)
> Code: e3a03000 e595404c e5c530c0 eaffffd7 (e7f001f2)
> ---[ end trace 5b6e58d2f7425625 ]---
>
> The issue is that all DMA cyclic users call "dmaengine_submit" just
> once [1], so only one descriptor is used and this descriptor is just
> looped until "dmaengine_terminateall" is called.
> It seems this BUG affects every use of a DMA cyclic transfer in the kernel.
>
> The implication of this is that the cookie of this descriptor is
> always 0 when "dma_cookie_complete" is called.
>
> I've temporally solved the problem in my local tree with this (dirty) patch:
> ---
> diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h
> index 17f983a..266e8ff 100644
> --- a/drivers/dma/dmaengine.h
> +++ b/drivers/dma/dmaengine.h
> @@ -52,7 +52,7 @@ static inline void dma_cookie_complete(struct
> dma_async_tx_descriptor *tx)
> {
> BUG_ON(tx->cookie < DMA_MIN_COOKIE);
> tx->chan->completed_cookie = tx->cookie;
> - tx->cookie = 0;
> +// tx->cookie = 0;
> }
>
> /**
> ---
>
> But I guess we need something cleaner here.
this is not right fix. The problem is that we shouldn't mark the cyclic
descriptor as complete. So for all drivers using cyclic API they should
do something like this. Can you test if this fixes your issue.
-----------------
diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
index a45b5d2..0c7362a 100644
--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -571,11 +571,14 @@ static void imxdma_tasklet(unsigned long data)
if (desc->desc.callback)
desc->desc.callback(desc->desc.callback_param);
- dma_cookie_complete(&desc->desc);
-
- /* If we are dealing with a cyclic descriptor keep it on ld_active */
+ /* If we are dealing with a cyclic descriptor keep it on ld_active
+ * and don't mark the descriptor as complete.
+ * Only in non-cyclic cases it would be marked as complete
+ */
if (imxdma_chan_is_doing_cyclic(imxdmac))
goto out;
+ else
+ dma_cookie_complete(&desc->desc);
/* Free 2D slot if it was an interleaved transfer */
if (imxdmac->enabled_2d) {
--
~Vinod
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [dmaengine] Cyclic DMA regression.
2012-04-05 6:08 ` Vinod Koul
@ 2012-04-09 7:09 ` javier Martin
2012-04-20 10:02 ` Vinod Koul
0 siblings, 1 reply; 4+ messages in thread
From: javier Martin @ 2012-04-09 7:09 UTC (permalink / raw)
To: Vinod Koul; +Cc: linux-kernel, Russell King, Sascha Hauer
On 5 April 2012 08:08, Vinod Koul <vinod.koul@linux.intel.com> wrote:
> this is not right fix. The problem is that we shouldn't mark the cyclic
> descriptor as complete. So for all drivers using cyclic API they should
> do something like this. Can you test if this fixes your issue.
> -----------------
> diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
> index a45b5d2..0c7362a 100644
> --- a/drivers/dma/imx-dma.c
> +++ b/drivers/dma/imx-dma.c
> @@ -571,11 +571,14 @@ static void imxdma_tasklet(unsigned long data)
> if (desc->desc.callback)
> desc->desc.callback(desc->desc.callback_param);
>
> - dma_cookie_complete(&desc->desc);
> -
> - /* If we are dealing with a cyclic descriptor keep it on ld_active */
> + /* If we are dealing with a cyclic descriptor keep it on ld_active
> + * and don't mark the descriptor as complete.
> + * Only in non-cyclic cases it would be marked as complete
> + */
> if (imxdma_chan_is_doing_cyclic(imxdmac))
> goto out;
> + else
> + dma_cookie_complete(&desc->desc);
>
> /* Free 2D slot if it was an interleaved transfer */
> if (imxdmac->enabled_2d) {
>
>
> --
> ~Vinod
>
Hi Vinod,
thank you for your patch.
It works fine for me:
Tested-by: Javier Martin <javier.martin@vista-silicon.com>
Could you apply it in your tree as a fix for 3.4?
Regards.
--
Javier Martin
Vista Silicon S.L.
CDTUC - FASE C - Oficina S-345
Avda de los Castros s/n
39005- Santander. Cantabria. Spain
+34 942 25 32 60
www.vista-silicon.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dmaengine] Cyclic DMA regression.
2012-04-09 7:09 ` javier Martin
@ 2012-04-20 10:02 ` Vinod Koul
0 siblings, 0 replies; 4+ messages in thread
From: Vinod Koul @ 2012-04-20 10:02 UTC (permalink / raw)
To: javier Martin; +Cc: linux-kernel, Russell King, Sascha Hauer
On Mon, 2012-04-09 at 09:09 +0200, javier Martin wrote:
> On 5 April 2012 08:08, Vinod Koul <vinod.koul@linux.intel.com> wrote:
> > this is not right fix. The problem is that we shouldn't mark the cyclic
> > descriptor as complete. So for all drivers using cyclic API they should
> > do something like this. Can you test if this fixes your issue.
> > -----------------
> > diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
> > index a45b5d2..0c7362a 100644
> > --- a/drivers/dma/imx-dma.c
> > +++ b/drivers/dma/imx-dma.c
> > @@ -571,11 +571,14 @@ static void imxdma_tasklet(unsigned long data)
> > if (desc->desc.callback)
> > desc->desc.callback(desc->desc.callback_param);
> >
> > - dma_cookie_complete(&desc->desc);
> > -
> > - /* If we are dealing with a cyclic descriptor keep it on ld_active */
> > + /* If we are dealing with a cyclic descriptor keep it on ld_active
> > + * and don't mark the descriptor as complete.
> > + * Only in non-cyclic cases it would be marked as complete
> > + */
> > if (imxdma_chan_is_doing_cyclic(imxdmac))
> > goto out;
> > + else
> > + dma_cookie_complete(&desc->desc);
> >
> > /* Free 2D slot if it was an interleaved transfer */
> > if (imxdmac->enabled_2d) {
> >
> >
> > --
> > ~Vinod
> >
>
> Hi Vinod,
> thank you for your patch.
>
> It works fine for me:
>
> Tested-by: Javier Martin <javier.martin@vista-silicon.com>
>
> Could you apply it in your tree as a fix for 3.4?
Thanks, Applied now
--
~Vinod
^ permalink raw reply [flat|nested] 4+ messages in thread
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2012-04-03 10:17 [dmaengine] Cyclic DMA regression javier Martin
2012-04-05 6:08 ` Vinod Koul
2012-04-09 7:09 ` javier Martin
2012-04-20 10:02 ` Vinod Koul
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