dma-engine: tegra210-adma: free dma controller

Following kernel panic is seen when DMA driver is loaded again
after removal.
===============================================================================
Unable to handle kernel paging request at virtual address ffffff8001198880
Internal error: Oops: 86000007 [#1] PREEMPT SMP
CPU: 0 PID: 5907 Comm: HwBinder:4123_1 Tainted: G C 4.9.128-tegra-g065839f #11
Hardware name: galen (DT)
task: ffffffc3590d1a80 task.stack: ffffffc3d0678000
PC is at 0xffffff8001198880
LR is at of_dma_request_slave_channel+0xd8/0x1f8
pc : [<ffffff8001198880>] lr : [<ffffff8008746f30>] pstate: 60400045
sp : ffffffc3d067b710
x29: ffffffc3d067b710 x28: 000000000000002f
x27: ffffff800949e000 x26: ffffff800949e750
x25: ffffff800949e000 x24: ffffffbefe817d84
x23: ffffff8009f77cb0 x22: 0000000000000028
x21: ffffffc3ffda49c8 x20: 0000000000000029
x19: 0000000000000001 x18: ffffffffffffffff
x17: 0000000000000000 x16: ffffff80082b66a0
x15: ffffff8009e78250 x14: 000000000000000a
x13: 0000000000000038 x12: 0101010101010101
x11: 0000000000000030 x10: 0101010101010101
x9 : fffffffffffffffc x8 : 7f7f7f7f7f7f7f7f
x7 : 62ff726b6b64622c x6 : 0000000000008064
x5 : 6400000000000000 x4 : ffffffbefe817c44
x3 : ffffffc3ffda3e08 x2 : ffffff8001198880
x1 : ffffffc3d48323c0 x0 : ffffffc3d067b788

Process HwBinder:4123_1 (pid: 5907, stack limit = 0xffffffc3d0678028)
Call trace:
[<ffffff8001198880>] 0xffffff8001198880
[<ffffff80087459f8>] dma_request_chan+0x50/0x1f0
[<ffffff8008745bc0>] dma_request_slave_channel+0x28/0x40
[<ffffff8001552c44>] tegra_alt_pcm_open+0x114/0x170 [snd_soc_tegra_alt_utils]
[<ffffff8008d65fa4>] soc_pcm_open+0x10c/0x878
[<ffffff8008d18618>] snd_pcm_open_substream+0xc0/0x170
[<ffffff8008d1878c>] snd_pcm_open+0xc4/0x240
[<ffffff8008d189e0>] snd_pcm_playback_open+0x58/0x80
[<ffffff8008cfc6d4>] snd_open+0xb4/0x178
[<ffffff8008250628>] chrdev_open+0xb8/0x1d0
[<ffffff8008246fdc>] do_dentry_open+0x214/0x318
[<ffffff80082485d0>] vfs_open+0x58/0x88
[<ffffff800825bce0>] do_last+0x450/0xde0
[<ffffff800825c718>] path_openat+0xa8/0x368
[<ffffff800825dd84>] do_filp_open+0x8c/0x110
[<ffffff8008248a74>] do_sys_open+0x164/0x220
[<ffffff80082b66dc>] compat_SyS_openat+0x3c/0x50
[<ffffff8008083040>] el0_svc_naked+0x34/0x38
---[ end trace 67e6d544e65b5145 ]---
Kernel panic - not syncing: Fatal exception
===============================================================================

The issue happens because in probe(), DMA controller is registed with DT DMA
helpers and the same is not freed during driver remove. During loading again
this results in memory abort and kernel panic happens.

This patch frees up resources with of_dma_controller_free() call in driver
remove.

Bug 200453666

Change-Id: I904b8f7d35b8e1fa16ec92764a48af84725f2bc0
Signed-off-by: spujar <spujar@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1851029
(cherry picked from commit 9e1270748244d375296eae9f16e23ee146d71bf0)
Reviewed-on: https://git-master.nvidia.com/r/1935134
GVS: Gerrit_Virtual_Submit
Reviewed-by: Mohan Kumar D <mkumard@nvidia.com>
Reviewed-by: Ravindra Lokhande <rlokhande@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
index e0f72e21a81157a728a3394cb2934fb365bed89a..772cee299678f71ebce87db7525c2ef63c557236 100644 (file)
--- a/drivers/dma/tegra210-adma.c
+++ b/drivers/dma/tegra210-adma.c
@@ -1431,7 +1431,9 @@ static int tegra_adma_remove(struct platform_device *pdev)
 {
        struct tegra_adma *tdma = platform_get_drvdata(pdev);
        int i;
+       struct device_node *node = pdev->dev.of_node;
 
+       of_dma_controller_free(node);
        dma_async_device_unregister(&tdma->dma_dev);
 
        for (i = 0; i < tdma->nr_channels; ++i)