[ 03/32] dma: imx-dma: Fix kernel crash due to missing clock conversion

From: Greg Kroah-Hartman
Date: Mon Aug 20 2012 - 00:16:14 EST

From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Fabio Estevam <festevam@xxxxxxxxx>

commit a2367db2ec5e7fc6fe93e221e0fcdee81b053daf upstream.

With the new i.MX clock infrastructure we need to request the dma clocks
seperately: ahb and ipg clocks.

This fixes the following kernel crash and make audio to be functional again:

root@freescale /home$ aplay audio48k16S.wav
Playing WAVE 'audio48k16S.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c7b74000
[00000000] *pgd=a7bb5831, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 Not tainted (3.5.0-rc5-next-20120702-00007-g3028b64 #1128)
PC is at snd_dmaengine_pcm_get_chan+0x8/0x10
LR is at snd_imx_pcm_hw_params+0x18/0xdc
pc : [<c02d3cf8>] lr : [<c02e95ec>] psr: a0000013
sp : c7b45e30 ip : ffffffff fp : c7ae58e0
r10: 00000000 r9 : c7ae981c r8 : c7b88800
r7 : c7ae5a60 r6 : c7ae5b20 r5 : c7ae9810 r4 : c7afa060
r3 : 00000000 r2 : 00000001 r1 : c7b88800 r0 : c7afa060
Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 0005317f Table: a7b74000 DAC: 00000015
Process aplay (pid: 701, stack limit = 0xc7b44270)
Stack: (0xc7b45e30 to 0xc7b46000)
5e20: 00100000 00000029 c7b88800 c02db870
5e40: c7ae5a60 c02d4594 00000010 01ae5a60 c7ae5a60 c7ae9810 c7ae9810 c7afa060
5e60: c7ae5b20 c7ae5a60 c7b88800 c02e3ef0 c02e3e08 c7b1e400 c7afa060 c7b88800
5e80: 00000000 c0014da8 c7b44000 00000000 bec566ac c02cd400 c7afa060 c7afa060
5ea0: bec56800 c7b88800 c0014da8 c02cdd7c c04ee710 c04ee7b8 00000003 c005fc74
5ec0: 00000000 7fffffff c7b45f00 c7afa060 c7b67420 c7ba3070 00000004 c0014da8
5ee0: c7b44000 00000000 bec566ac c02ced88 c04e95f8 b6f5ab04 c7b45fb0 0145a468
5f00: 0145a600 bec566bc bec56800 c7b67420 c7ba3070 c00d499c c7b45f18 c7b45f18
5f20: 0000001a 00000004 00000001 c7b44000 c0527f40 00000009 00000008 00000000
5f40: c7b44000 c002c9ec 00000001 c04f0ab0 c04ebec0 00000101 00000000 0000000a
5f60: 60000093 c7b67420 bec56800 c25c4111 00000004 c0014da8 c7b44000 00000000
5f80: bec566ac c00d4f38 b6ffb658 00000000 c0522d80 0145a468 b6fd5000 0145a418
5fa0: 00000036 c0014c00 0145a468 b6fd5000 00000004 c25c4111 bec56800 00020001
5fc0: 0145a468 b6fd5000 0145a418 00000036 0145a468 0145a600 bec566bc bec566ac
5fe0: 0145a468 bec56388 b6f65ce4 b6dcebec 20000010 00000004 00000000 00000000
[<c02d3cf8>] (snd_dmaengine_pcm_get_chan+0x8/0x10) from [<c02e95ec>] (snd_imx_pcm_hw_params+0x18/0xdc)
[<c02e95ec>] (snd_imx_pcm_hw_params+0x18/0xdc) from [<c02e3ef0>] (soc_pcm_hw_params+0xe8/0x1f0)
[<c02e3ef0>] (soc_pcm_hw_params+0xe8/0x1f0) from [<c02cd400>] (snd_pcm_hw_params+0x124/0x474)
[<c02cd400>] (snd_pcm_hw_params+0x124/0x474) from [<c02cdd7c>] (snd_pcm_common_ioctl1+0x4b4/0xf74)
[<c02cdd7c>] (snd_pcm_common_ioctl1+0x4b4/0xf74) from [<c02ced88>] (snd_pcm_playback_ioctl1+0x30/0x510)
[<c02ced88>] (snd_pcm_playback_ioctl1+0x30/0x510) from [<c00d499c>] (do_vfs_ioctl+0x80/0x5e4)
[<c00d499c>] (do_vfs_ioctl+0x80/0x5e4) from [<c00d4f38>] (sys_ioctl+0x38/0x60)
[<c00d4f38>] (sys_ioctl+0x38/0x60) from [<c0014c00>] (ret_fast_syscall+0x0/0x2c)
Code: e593000c e12fff1e e59030a0 e59330bc (e5930000)
---[ end trace fa518c8ba3a74e97 ]--

Reported-by: Javier Martin <javier.martin@xxxxxxxxxxxxxxxxx>
Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
Acked-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/dma/imx-dma.c | 36 +++++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 11 deletions(-)

--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -172,7 +172,8 @@ struct imxdma_engine {
struct device_dma_parameters dma_parms;
struct dma_device dma_device;
void __iomem *base;
- struct clk *dma_clk;
+ struct clk *dma_ahb;
+ struct clk *dma_ipg;
spinlock_t lock;
struct imx_dma_2d_config slots_2d[IMX_DMA_2D_SLOTS];
struct imxdma_channel channel[IMX_DMA_CHANNELS];
@@ -976,10 +977,20 @@ static int __init imxdma_probe(struct pl
return 0;
}

- imxdma->dma_clk = clk_get(NULL, "dma");
- if (IS_ERR(imxdma->dma_clk))
- return PTR_ERR(imxdma->dma_clk);
- clk_enable(imxdma->dma_clk);
+ imxdma->dma_ipg = devm_clk_get(&pdev->dev, "ipg");
+ if (IS_ERR(imxdma->dma_ipg)) {
+ ret = PTR_ERR(imxdma->dma_ipg);
+ goto err_clk;
+ }
+
+ imxdma->dma_ahb = devm_clk_get(&pdev->dev, "ahb");
+ if (IS_ERR(imxdma->dma_ahb)) {
+ ret = PTR_ERR(imxdma->dma_ahb);
+ goto err_clk;
+ }
+
+ clk_prepare_enable(imxdma->dma_ipg);
+ clk_prepare_enable(imxdma->dma_ahb);

/* reset DMA module */
imx_dmav1_writel(imxdma, DCR_DRST, DMA_DCR);
@@ -988,16 +999,14 @@ static int __init imxdma_probe(struct pl
ret = request_irq(MX1_DMA_INT, dma_irq_handler, 0, "DMA", imxdma);
if (ret) {
dev_warn(imxdma->dev, "Can't register IRQ for DMA\n");
- kfree(imxdma);
- return ret;
+ goto err_enable;
}

ret = request_irq(MX1_DMA_ERR, imxdma_err_handler, 0, "DMA", imxdma);
if (ret) {
dev_warn(imxdma->dev, "Can't register ERRIRQ for DMA\n");
free_irq(MX1_DMA_INT, NULL);
- kfree(imxdma);
- return ret;
+ goto err_enable;
}
}

@@ -1094,7 +1103,10 @@ err_init:
free_irq(MX1_DMA_INT, NULL);
free_irq(MX1_DMA_ERR, NULL);
}
-
+err_enable:
+ clk_disable_unprepare(imxdma->dma_ipg);
+ clk_disable_unprepare(imxdma->dma_ahb);
+err_clk:
kfree(imxdma);
return ret;
}
@@ -1114,7 +1126,9 @@ static int __exit imxdma_remove(struct p
free_irq(MX1_DMA_ERR, NULL);
}

- kfree(imxdma);
+ clk_disable_unprepare(imxdma->dma_ipg);
+ clk_disable_unprepare(imxdma->dma_ahb);
+ kfree(imxdma);

return 0;
}


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