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* [PATCH] dmaengine: rcar-dmac: Handle hardware descriptor allocation failure
@ 2014-11-25 14:10 ` Jürg Billeter
  0 siblings, 0 replies; 35+ messages in thread
From: Jürg Billeter @ 2014-11-25 14:10 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Simon Horman, Magnus Damm, Vinod Koul, Phil Edworthy,
	Kuninori Morimoto, linux-kernel, linux-sh, dmaengine,
	Jürg Billeter

If the atomic DMA coherent pool is too small, disable use of hardware
descriptor lists instead of crashing the system:

ERROR: 256 KiB atomic DMA coherent pool is too small!
Please increase it with coherent_pool= kernel parameter!

Unable to handle kernel NULL pointer dereference at virtual address 00000004
Internal error: Oops: a07 [#1] PREEMPT SMP ARM

PC is at rcar_dmac_chan_reinit+0x3c/0x160
LR is at _raw_spin_lock_irqsave+0x18/0x5c

[<802132c0>] (rcar_dmac_chan_reinit) from [<80214818>] (rcar_dmac_isr_error+0x84/0xa0)
[<80214818>] (rcar_dmac_isr_error) from [<80060484>] (handle_irq_event_percpu+0x50/0x150)
[<80060484>] (handle_irq_event_percpu) from [<800605c0>] (handle_irq_event+0x3c/0x5c)
[<800605c0>] (handle_irq_event) from [<8006350c>] (handle_fasteoi_irq+0xb8/0x198)
[<8006350c>] (handle_fasteoi_irq) from [<8005fdb0>] (generic_handle_irq+0x20/0x30)
[<8005fdb0>] (generic_handle_irq) from [<8000fcd0>] (handle_IRQ+0x50/0xc4)
[<8000fcd0>] (handle_IRQ) from [<800092cc>] (gic_handle_irq+0x28/0x5c)
[<800092cc>] (gic_handle_irq) from [<80012700>] (__irq_svc+0x40/0x70)

Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: Jürg Billeter <j@bitron.ch>
---
 drivers/dma/sh/rcar-dmac.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index f8f70eb..f18b1b6 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -679,8 +679,8 @@ static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan,
 	desc->hwdescs.size = size;
 }
 
-static void rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan,
-				  struct rcar_dmac_desc *desc)
+static int rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan,
+				 struct rcar_dmac_desc *desc)
 {
 	struct rcar_dmac_xfer_chunk *chunk;
 	struct rcar_dmac_hw_desc *hwdesc;
@@ -689,7 +689,7 @@ static void rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan,
 
 	hwdesc = desc->hwdescs.mem;
 	if (!hwdesc)
-		return;
+		return -ENOMEM;
 
 	list_for_each_entry(chunk, &desc->chunks, node) {
 		hwdesc->sar = chunk->src_addr;
@@ -697,6 +697,8 @@ static void rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan,
 		hwdesc->tcr = chunk->size >> desc->xfer_shift;
 		hwdesc++;
 	}
+
+	return 0;
 }
 
 /* -----------------------------------------------------------------------------
@@ -933,8 +935,10 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
 	 * additional complexity remains to be investigated.
 	 */
 	desc->hwdescs.use = !highmem && nchunks > 1;
-	if (desc->hwdescs.use)
-		rcar_dmac_fill_hwdesc(chan, desc);
+	if (desc->hwdescs.use) {
+		if (rcar_dmac_fill_hwdesc(chan, desc) < 0)
+			desc->hwdescs.use = false;
+	}
 
 	return &desc->async_tx;
 }
-- 
2.1.3


^ permalink raw reply related	[flat|nested] 35+ messages in thread

end of thread, other threads:[~2014-12-23  9:14 UTC | newest]

Thread overview: 35+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-11-25 14:10 [PATCH] dmaengine: rcar-dmac: Handle hardware descriptor allocation failure Jürg Billeter
2014-11-25 14:10 ` Jürg Billeter
2014-11-27  0:07 ` Laurent Pinchart
2014-11-27  0:07   ` Laurent Pinchart
2014-12-08 11:36 ` Vinod Koul
2014-12-08 11:48   ` Vinod Koul
2014-12-08 16:50   ` Jürg Billeter
2014-12-08 16:50     ` Jürg Billeter
2014-12-08 17:19     ` Vinod Koul
2014-12-08 17:31       ` Vinod Koul
2014-12-08 17:40       ` Laurent Pinchart
2014-12-08 17:40         ` Laurent Pinchart
2014-12-08 17:50         ` Vinod Koul
2014-12-08 17:50           ` Vinod Koul
2014-12-09  6:39           ` Vinod Koul
2014-12-09  6:51             ` Vinod Koul
2014-12-10 16:09             ` Laurent Pinchart
2014-12-10 16:09               ` Laurent Pinchart
2014-12-11  1:16               ` Kuninori Morimoto
2014-12-12 19:41                 ` Laurent Pinchart
2014-12-12 19:41                   ` Laurent Pinchart
2014-12-15  6:38                   ` Vinod Koul
2014-12-15  6:50                     ` Vinod Koul
2014-12-15 20:04                     ` Laurent Pinchart
2014-12-15 20:04                       ` Laurent Pinchart
2014-12-16  7:04                       ` Vinod Koul
2014-12-16  7:16                         ` Vinod Koul
2014-12-16 23:57                         ` Laurent Pinchart
2014-12-16 23:57                           ` Laurent Pinchart
2014-12-17 12:54                           ` Vinod Koul
2014-12-17 12:54                             ` Vinod Koul
2014-12-22 15:02                             ` Vinod Koul
2014-12-22 15:14                               ` Vinod Koul
2014-12-23  9:14                               ` Laurent Pinchart
2014-12-23  9:14                                 ` Laurent Pinchart

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