[PATCH AUTOSEL 4.14 008/167] dmaengine: tegra210-dma: free dma controller in remove()

[PATCH AUTOSEL 4.14 008/167] dmaengine: tegra210-dma: free dma controller in remove()

[Sasha Levin]

From: Sameer Pujar <spujar@nvidia.com>

[ Upstream commit f030e419501cb95e961e9ed35c493b5d46a04eca ]

Following kernel panic is seen during DMA driver unload->load sequence
==========================================================================
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
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
[<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
==========================================================================

In device probe(), of_dma_controller_register() registers DMA controller.
But when driver is removed, this is not freed. During driver reload this
results in data abort and kernel panic. Add of_dma_controller_free() in
driver remove path to fix the issue.

Fixes: f46b195799b5 ("dmaengine: tegra-adma: Add support for Tegra210 ADMA")
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/tegra210-adma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
index b26256f23d67f..08b10274284a8 100644
--- a/drivers/dma/tegra210-adma.c
+++ b/drivers/dma/tegra210-adma.c
@@ -786,6 +786,7 @@ static int tegra_adma_remove(struct platform_device *pdev)
 	struct tegra_adma *tdma = platform_get_drvdata(pdev);
 	int i;
 
+	of_dma_controller_free(pdev->dev.of_node);
 	dma_async_device_unregister(&tdma->dma_dev);
 
 	for (i = 0; i < tdma->nr_channels; ++i)
-- 
2.20.1

[PATCH AUTOSEL 4.14 033/167] dmaengine: pl330: _stop: clear interrupt status

[Sasha Levin]

From: Sugar Zhang <sugar.zhang@rock-chips.com>

[ Upstream commit 2da254cc7908105a60a6bb219d18e8dced03dcb9 ]

This patch kill instructs the DMAC to immediately terminate
execution of a thread. and then clear the interrupt status,
at last, stop generating interrupts for DMA_SEV. to guarantee
the next dma start is clean. otherwise, one interrupt maybe leave
to next start and make some mistake.

we can reporduce the problem as follows:

DMASEV: modify the event-interrupt resource, and if the INTEN sets
function as interrupt, the DMAC will set irq<event_num> HIGH to
generate interrupt. write INTCLR to clear interrupt.

	DMA EXECUTING INSTRUCTS		DMA TERMINATE
		|				|
		|				|
	       ...			      _stop
		|				|
		|			spin_lock_irqsave
	     DMASEV				|
		|				|
		|			    mask INTEN
		|				|
		|			     DMAKILL
		|				|
		|			spin_unlock_irqrestore

in above case, a interrupt was left, and if we unmask INTEN, the DMAC
will set irq<event_num> HIGH to generate interrupt.

to fix this, do as follows:

	DMA EXECUTING INSTRUCTS		DMA TERMINATE
		|				|
		|				|
	       ...			      _stop
		|				|
		|			spin_lock_irqsave
	     DMASEV				|
		|				|
		|			     DMAKILL
		|				|
		|			   clear INTCLR
		|			    mask INTEN
		|				|
		|			spin_unlock_irqrestore

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/pl330.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 6afd42cfbf5d5..b4fa555a243f9 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -960,6 +960,7 @@ static void _stop(struct pl330_thread *thrd)
 {
 	void __iomem *regs = thrd->dmac->base;
 	u8 insn[6] = {0, 0, 0, 0, 0, 0};
+	u32 inten = readl(regs + INTEN);
 
 	if (_state(thrd) == PL330_STATE_FAULT_COMPLETING)
 		UNTIL(thrd, PL330_STATE_FAULTING | PL330_STATE_KILLING);
@@ -972,10 +973,13 @@ static void _stop(struct pl330_thread *thrd)
 
 	_emit_KILL(0, insn);
 
-	/* Stop generating interrupts for SEV */
-	writel(readl(regs + INTEN) & ~(1 << thrd->ev), regs + INTEN);
-
 	_execute_DBGINSN(thrd, insn, is_manager(thrd));
+
+	/* clear the event */
+	if (inten & (1 << thrd->ev))
+		writel(1 << thrd->ev, regs + INTCLR);
+	/* Stop generating interrupts for SEV */
+	writel(inten & ~(1 << thrd->ev), regs + INTEN);
 }
 
 /* Start doing req 'idx' of thread 'thrd' */
-- 
2.20.1

[PATCH AUTOSEL 4.14 058/167] dmaengine: at_xdmac: remove BUG_ON macro in tasklet

[Sasha Levin]

From: Nicolas Ferre <nicolas.ferre@microchip.com>

[ Upstream commit e2c114c06da2d9ffad5b16690abf008d6696f689 ]

Even if this case shouldn't happen when controller is properly programmed,
it's still better to avoid dumping a kernel Oops for this.
As the sequence may happen only for debugging purposes, log the error and
just finish the tasklet call.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/at_xdmac.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 4db2cd1c611de..22764cd30cc39 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1606,7 +1606,11 @@ static void at_xdmac_tasklet(unsigned long data)
 					struct at_xdmac_desc,
 					xfer_node);
 		dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
-		BUG_ON(!desc->active_xfer);
+		if (!desc->active_xfer) {
+			dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
+			spin_unlock_bh(&atchan->lock);
+			return;
+		}
 
 		txd = &desc->tx_dma_desc;
 
-- 
2.20.1