* [PATCH] ARM: dts: exynos4: add DMA support for serial ports
@ 2015-06-29 13:22 Robert Baldyga
2015-06-30 0:56 ` Krzysztof Kozlowski
0 siblings, 1 reply; 3+ messages in thread
From: Robert Baldyga @ 2015-06-29 13:22 UTC (permalink / raw)
To: linux-arm-kernel
Enable DMA transfers for serial ports.
Signed-off-by: Robert Baldyga <r.baldyga@samsung•com>
---
arch/arm/boot/dts/exynos4.dtsi | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm/boot/dts/exynos4.dtsi b/arch/arm/boot/dts/exynos4.dtsi
index e20cdc2..21b839b 100644
--- a/arch/arm/boot/dts/exynos4.dtsi
+++ b/arch/arm/boot/dts/exynos4.dtsi
@@ -426,6 +426,8 @@
interrupts = <0 52 0>;
clocks = <&clock CLK_UART0>, <&clock CLK_SCLK_UART0>;
clock-names = "uart", "clk_uart_baud0";
+ dmas = <&pdma0 15>, <&pdma0 16>;
+ dma-names = "rx", "tx";
status = "disabled";
};
@@ -435,6 +437,8 @@
interrupts = <0 53 0>;
clocks = <&clock CLK_UART1>, <&clock CLK_SCLK_UART1>;
clock-names = "uart", "clk_uart_baud0";
+ dmas = <&pdma1 15>, <&pdma1 16>;
+ dma-names = "rx", "tx";
status = "disabled";
};
@@ -444,6 +448,8 @@
interrupts = <0 54 0>;
clocks = <&clock CLK_UART2>, <&clock CLK_SCLK_UART2>;
clock-names = "uart", "clk_uart_baud0";
+ dmas = <&pdma0 17>, <&pdma0 18>;
+ dma-names = "rx", "tx";
status = "disabled";
};
@@ -453,6 +459,8 @@
interrupts = <0 55 0>;
clocks = <&clock CLK_UART3>, <&clock CLK_SCLK_UART3>;
clock-names = "uart", "clk_uart_baud0";
+ dmas = <&pdma1 17>, <&pdma1 18>;
+ dma-names = "rx", "tx";
status = "disabled";
};
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] ARM: dts: exynos4: add DMA support for serial ports
2015-06-29 13:22 [PATCH] ARM: dts: exynos4: add DMA support for serial ports Robert Baldyga
@ 2015-06-30 0:56 ` Krzysztof Kozlowski
2015-07-07 1:41 ` Krzysztof Kozlowski
0 siblings, 1 reply; 3+ messages in thread
From: Krzysztof Kozlowski @ 2015-06-30 0:56 UTC (permalink / raw)
To: linux-arm-kernel
On 29.06.2015 22:22, Robert Baldyga wrote:
> Enable DMA transfers for serial ports.
>
> Signed-off-by: Robert Baldyga <r.baldyga@samsung•com>
> ---
> arch/arm/boot/dts/exynos4.dtsi | 8 ++++++++
> 1 file changed, 8 insertions(+)
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung•com>
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] ARM: dts: exynos4: add DMA support for serial ports
2015-06-30 0:56 ` Krzysztof Kozlowski
@ 2015-07-07 1:41 ` Krzysztof Kozlowski
0 siblings, 0 replies; 3+ messages in thread
From: Krzysztof Kozlowski @ 2015-07-07 1:41 UTC (permalink / raw)
To: linux-arm-kernel
2015-06-30 9:56 GMT+09:00 Krzysztof Kozlowski <k.kozlowski@samsung•com>:
> On 29.06.2015 22:22, Robert Baldyga wrote:
>> Enable DMA transfers for serial ports.
>>
>> Signed-off-by: Robert Baldyga <r.baldyga@samsung•com>
>> ---
>> arch/arm/boot/dts/exynos4.dtsi | 8 ++++++++
>> 1 file changed, 8 insertions(+)
>
> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung•com>
Unfortunately the commit (applied on 4.2-rc1) exposes lock-ups during
Trats2 boot.
Board: Trats2
Config: exynos
Tree: https://github.com/krzk/linux.git
branch: for-next (v4.2-rc1-29-g1ce41c343055)
Lockdep indicated issue in Samsung serial driver
(dma_async_issue_pending called while holding port->lock which leads
to calling back the driver's tx_dma_complete).
I tried to locate the dead lock. To me the excessive locking in serial
driver causes such recursive locking but I am not quite sure (I am not
familiar with the serial driver).
Anyway, till this get fixed I am dropping the patch from my tree.
Best regards,
Krzysztof
Bug (I hope line wrapping won't mess up with it...):
[ 74.480535] BUG: spinlock recursion on CPU#1, systemd/1
[ 74.484293] lock: 0xeeb1a9f4, .magic: dead4ead, .owner: systemd/1,
.owner_cpu: 1
[ 74.491756] CPU: 1 PID: 1 Comm: systemd Not tainted
4.2.0-rc1-00029-g1ce41c343055 #100
[ 74.499649] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 74.505752] [<c0014d2c>] (unwind_backtrace) from [<c0011c98>]
(show_stack+0x10/0x14)
[ 74.513461] [<c0011c98>] (show_stack) from [<c051f198>]
(dump_stack+0x70/0xbc)
[ 74.520668] [<c051f198>] (dump_stack) from [<c00562b0>]
(do_raw_spin_lock+0x178/0x1a0)
[ 74.528568] [<c00562b0>] (do_raw_spin_lock) from [<c0524e90>]
(_raw_spin_lock_irqsave+0x20/0x28)
[ 74.537330] [<c0524e90>] (_raw_spin_lock_irqsave) from [<c024288c>]
(dma_pl330_rqcb.isra.4+0x24/0x58)
[ 74.546529] [<c024288c>] (dma_pl330_rqcb.isra.4) from [<c0242d78>]
(pl330_release_channel.part.5+0x38/0x98)
[ 74.556249] [<c0242d78>] (pl330_release_channel.part.5) from
[<c0242e2c>] (pl330_free_chan_resources+0x54/0xd8)
[ 74.566324] [<c0242e2c>] (pl330_free_chan_resources) from
[<c0240144>] (dma_chan_put+0x88/0x8c)
[ 74.575001] [<c0240144>] (dma_chan_put) from [<c024016c>]
(dma_release_channel+0x24/0x94)
[ 74.583163] [<c024016c>] (dma_release_channel) from [<c0271498>]
(s3c24xx_serial_shutdown+0x18c/0x1d8)
[ 74.592447] [<c0271498>] (s3c24xx_serial_shutdown) from
[<c026ab28>] (uart_port_shutdown+0x2c/0x38)
[ 74.601472] [<c026ab28>] (uart_port_shutdown) from [<c026acc4>]
(uart_shutdown+0xac/0xec)
[ 74.609630] [<c026acc4>] (uart_shutdown) from [<c026ae3c>]
(uart_close+0x64/0x1f0)
[ 74.617184] [<c026ae3c>] (uart_close) from [<c0251544>]
(tty_release+0xf0/0x464)
[ 74.624566] [<c0251544>] (tty_release) from [<c00cca38>] (__fput+0x80/0x1bc)
[ 74.631594] [<c00cca38>] (__fput) from [<c00384d0>] (task_work_run+0xa8/0xdc)
[ 74.638711] [<c00384d0>] (task_work_run) from [<c00118dc>]
(do_work_pending+0x94/0xb4)
[ 74.646610] [<c00118dc>] (do_work_pending) from [<c000f54c>]
(work_pending+0xc/0x20)
Lockdep:
[ 109.696678] #### Requested RX ee0d4a2c at TX ee0d4ac4
[ 109.701699]
[ 109.701928] =============================================
[ 109.707310] [ INFO: possible recursive locking detected ]
[ 109.712694] 4.2.0-rc1-00029-g1ce41c343055-dirty #111 Not tainted
[ 109.718680] ---------------------------------------------
[ 109.724063] swapper/0/0 is trying to acquire lock:
[ 109.728836] (&port_lock_key){-.-...}, at: [<c02ad78c>]
s3c24xx_serial_tx_dma_complete+0x8c/0xfc
[ 109.737603]
[ 109.737603] but task is already holding lock:
[ 109.743418] (&port_lock_key){-.-...}, at: [<c02ac014>]
s3c24xx_serial_tx_chars+0x18/0x180
[ 109.751664]
[ 109.751664] other info that might help us debug this:
[ 109.758174] Possible unsafe locking scenario:
[ 109.758174]
[ 109.764076] CPU0
[ 109.766507] ----
[ 109.768936] lock(&port_lock_key);
[ 109.772408] lock(&port_lock_key);
[ 109.775881]
[ 109.775881] *** DEADLOCK ***
[ 109.775881]
[ 109.781784] May be due to missing lock nesting notation
[ 109.781784]
[ 109.788556] 1 lock held by swapper/0/0:
[ 109.792373] #0: (&port_lock_key){-.-...}, at: [<c02ac014>]
s3c24xx_serial_tx_chars+0x18/0x180
[ 109.801053]
[ 109.801053] stack backtrace:
[ 109.805399] CPU: 0 PID: 0 Comm: swapper/0 Not tainted
4.2.0-rc1-00029-g1ce41c343055-dirty #111
[ 109.813988] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 109.820084] [<c0015e9c>] (unwind_backtrace) from [<c0012c18>]
(show_stack+0x10/0x14)
[ 109.827801] [<c0012c18>] (show_stack) from [<c0599b7c>]
(dump_stack+0x70/0xbc)
[ 109.835003] [<c0599b7c>] (dump_stack) from [<c00649ec>]
(validate_chain.isra.24+0x7b4/0x8b8)
[ 109.843419] [<c00649ec>] (validate_chain.isra.24) from [<c00656c4>]
(__lock_acquire+0x464/0xb28)
[ 109.852185] [<c00656c4>] (__lock_acquire) from [<c0066100>]
(lock_acquire+0x6c/0x8c)
[ 109.859915] [<c0066100>] (lock_acquire) from [<c05a0e68>]
(_raw_spin_lock_irqsave+0x48/0x5c)
[ 109.868335] [<c05a0e68>] (_raw_spin_lock_irqsave) from [<c02ad78c>]
(s3c24xx_serial_tx_dma_complete+0x8c/0xfc)
[ 109.878322] [<c02ad78c>] (s3c24xx_serial_tx_dma_complete) from
[<c027b57c>] (pl330_tasklet+0x16c/0x4cc)
[ 109.887690] [<c027b57c>] (pl330_tasklet) from [<c02abf4c>]
(s3c24xx_serial_start_tx_dma+0x1a4/0x1f4)
[ 109.896803] [<c02abf4c>] (s3c24xx_serial_start_tx_dma) from
[<c02ac154>] (s3c24xx_serial_tx_chars+0x158/0x180)
[ 109.906784] [<c02ac154>] (s3c24xx_serial_tx_chars) from
[<c02ad5ec>] (s3c64xx_serial_handle_irq+0x34/0x60)
[ 109.916424] [<c02ad5ec>] (s3c64xx_serial_handle_irq) from
[<c0070f7c>] (handle_irq_event_percpu+0x50/0x154)
[ 109.926142] [<c0070f7c>] (handle_irq_event_percpu) from
[<c00710c0>] (handle_irq_event+0x40/0x64)
[ 109.934995] [<c00710c0>] (handle_irq_event) from [<c0073fec>]
(handle_fasteoi_irq+0xdc/0x1a4)
[ 109.943501] [<c0073fec>] (handle_fasteoi_irq) from [<c0070850>]
(generic_handle_irq+0x20/0x30)
[ 109.952095] [<c0070850>] (generic_handle_irq) from [<c007096c>]
(__handle_domain_irq+0x6c/0xe4)
[ 109.960774] [<c007096c>] (__handle_domain_irq) from [<c0009474>]
(gic_handle_irq+0x2c/0x68)
[ 109.969105] [<c0009474>] (gic_handle_irq) from [<c0013744>]
(__irq_svc+0x44/0x7c)
[ 109.976566] Exception stack(0xc085df28 to 0xc085df70)
[ 109.981603] df20: 00000001 00000001 00000000
c0860e78 8a83f452 00000019
[ 109.989763] df40: 8a95ae3e 00000019 eef70490 c088b8c4 00000000
c088b8c4 00000000 c085df70
[ 109.997919] df60: c0066a34 c04154b4 200b0013 ffffffff
[ 110.002965] [<c0013744>] (__irq_svc) from [<c04154b4>]
(cpuidle_enter_state+0x1f8/0x28c)
[ 110.011037] [<c04154b4>] (cpuidle_enter_state) from [<c005d464>]
(cpu_startup_entry+0x158/0x26c)
[ 110.019804] [<c005d464>] (cpu_startup_entry) from [<c07f8c48>]
(start_kernel+0x370/0x3dc)
[ 120.694973] BUG: spinlock lockup suspected on CPU#0, swapper/0/0
[ 120.699509] lock: s3c24xx_serial_ports+0x2dc/0x560, .magic:
dead4ead, .owner: swapper/0/0, .owner_cpu: 0
[ 120.709050] CPU: 0 PID: 0 Comm: swapper/0 Not tainted
4.2.0-rc1-00029-g1ce41c343055-dirty #111
[ 120.717638] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 120.723727] [<c0015e9c>] (unwind_backtrace) from [<c0012c18>]
(show_stack+0x10/0x14)
[ 120.731450] [<c0012c18>] (show_stack) from [<c0599b7c>]
(dump_stack+0x70/0xbc)
[ 120.738652] [<c0599b7c>] (dump_stack) from [<c0069ca4>]
(do_raw_spin_lock+0x114/0x1a0)
[ 120.746552] [<c0069ca4>] (do_raw_spin_lock) from [<c05a0e70>]
(_raw_spin_lock_irqsave+0x50/0x5c)
[ 120.755321] [<c05a0e70>] (_raw_spin_lock_irqsave) from [<c02ad78c>]
(s3c24xx_serial_tx_dma_complete+0x8c/0xfc)
[ 120.765304] [<c02ad78c>] (s3c24xx_serial_tx_dma_complete) from
[<c027b57c>] (pl330_tasklet+0x16c/0x4cc)
[ 120.774675] [<c027b57c>] (pl330_tasklet) from [<c02abf4c>]
(s3c24xx_serial_start_tx_dma+0x1a4/0x1f4)
[ 120.783788] [<c02abf4c>] (s3c24xx_serial_start_tx_dma) from
[<c02ac154>] (s3c24xx_serial_tx_chars+0x158/0x180)
[ 120.793770] [<c02ac154>] (s3c24xx_serial_tx_chars) from
[<c02ad5ec>] (s3c64xx_serial_handle_irq+0x34/0x60)
[ 120.803408] [<c02ad5ec>] (s3c64xx_serial_handle_irq) from
[<c0070f7c>] (handle_irq_event_percpu+0x50/0x154)
[ 120.813128] [<c0070f7c>] (handle_irq_event_percpu) from
[<c00710c0>] (handle_irq_event+0x40/0x64)
[ 120.821980] [<c00710c0>] (handle_irq_event) from [<c0073fec>]
(handle_fasteoi_irq+0xdc/0x1a4)
[ 120.830486] [<c0073fec>] (handle_fasteoi_irq) from [<c0070850>]
(generic_handle_irq+0x20/0x30)
[ 120.839080] [<c0070850>] (generic_handle_irq) from [<c007096c>]
(__handle_domain_irq+0x6c/0xe4)
[ 120.847759] [<c007096c>] (__handle_domain_irq) from [<c0009474>]
(gic_handle_irq+0x2c/0x68)
[ 120.856090] [<c0009474>] (gic_handle_irq) from [<c0013744>]
(__irq_svc+0x44/0x7c)
[ 120.863550] Exception stack(0xc085df28 to 0xc085df70)
[ 120.868588] df20: 00000001 00000001 00000000
c0860e78 8a83f452 00000019
[ 120.876748] df40: 8a95ae3e 00000019 eef70490 c088b8c4 00000000
c088b8c4 00000000 c085df70
[ 120.884904] df60: c0066a34 c04154b4 200b0013 ffffffff
[ 120.889946] [<c0013744>] (__irq_svc) from [<c04154b4>]
(cpuidle_enter_state+0x1f8/0x28c)
[ 120.898019] [<c04154b4>] (cpuidle_enter_state) from [<c005d464>]
(cpu_startup_entry+0x158/0x26c)
[ 120.906785] [<c005d464>] (cpu_startup_entry) from [<c07f8c48>]
(start_kernel+0x370/0x3dc)
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-06-29 13:22 [PATCH] ARM: dts: exynos4: add DMA support for serial ports Robert Baldyga
2015-06-30 0:56 ` Krzysztof Kozlowski
2015-07-07 1:41 ` Krzysztof Kozlowski
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