On 20/01/2025 16:41, Ronald Wahl wrote:
> From: Ronald Wahl <ronald.wahl@xxxxxxxxxxx>
>
> Recent kernels complain about a missing lock in k3-udma.c when the lock
> validator is enabled:
>
> [ 4.128073] WARNING: CPU: 0 PID: 746 at drivers/dma/ti/../virt-dma.h:169 udma_start.isra.0+0x34/0x238
> [ 4.137352] CPU: 0 UID: 0 PID: 746 Comm: kworker/0:3 Not tainted 6.12.9-arm64 #28
> [ 4.144867] Hardware name: pp-v12 (DT)
> [ 4.148648] Workqueue: events udma_check_tx_completion
> [ 4.153841] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [ 4.160834] pc : udma_start.isra.0+0x34/0x238
> [ 4.165227] lr : udma_start.isra.0+0x30/0x238
> [ 4.169618] sp : ffffffc083cabcf0
> [ 4.172963] x29: ffffffc083cabcf0 x28: 0000000000000000 x27: ffffff800001b005
> [ 4.180167] x26: ffffffc0812f0000 x25: 0000000000000000 x24: 0000000000000000
> [ 4.187370] x23: 0000000000000001 x22: 00000000e21eabe9 x21: ffffff8000fa0670
> [ 4.194571] x20: ffffff8001b6bf00 x19: ffffff8000fa0430 x18: ffffffc083b95030
> [ 4.201773] x17: 0000000000000000 x16: 00000000f0000000 x15: 0000000000000048
> [ 4.208976] x14: 0000000000000048 x13: 0000000000000000 x12: 0000000000000001
> [ 4.216179] x11: ffffffc08151a240 x10: 0000000000003ea1 x9 : ffffffc08046ab68
> [ 4.223381] x8 : ffffffc083cabac0 x7 : ffffffc081df3718 x6 : 0000000000029fc8
> [ 4.230583] x5 : ffffffc0817ee6d8 x4 : 0000000000000bc0 x3 : 0000000000000000
> [ 4.237784] x2 : 0000000000000000 x1 : 00000000001fffff x0 : 0000000000000000
> [ 4.244986] Call trace:
> [ 4.247463] udma_start.isra.0+0x34/0x238
> [ 4.251509] udma_check_tx_completion+0xd0/0xdc
> [ 4.256076] process_one_work+0x244/0x3fc
> [ 4.260129] process_scheduled_works+0x6c/0x74
> [ 4.264610] worker_thread+0x150/0x1dc
> [ 4.268398] kthread+0xd8/0xe8
> [ 4.271492] ret_from_fork+0x10/0x20
> [ 4.275107] irq event stamp: 220
> [ 4.278363] hardirqs last enabled at (219): [<ffffffc080a27c7c>] _raw_spin_unlock_irq+0x38/0x50
> [ 4.287183] hardirqs last disabled at (220): [<ffffffc080a1c154>] el1_dbg+0x24/0x50
> [ 4.294879] softirqs last enabled at (182): [<ffffffc080037e68>] handle_softirqs+0x1c0/0x3cc
> [ 4.303437] softirqs last disabled at (177): [<ffffffc080010170>] __do_softirq+0x1c/0x28
> [ 4.311559] ---[ end trace 0000000000000000 ]---
>
> This commit adds the missing locking.
Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
>
> Fixes: 25dcb5dd7b7c ("dmaengine: ti: New driver for K3 UDMA")
> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
> Cc: Vignesh Raghavendra <vigneshr@xxxxxx>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: dmaengine@xxxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Ronald Wahl <ronald.wahl@xxxxxxxxxxx>
> ---
> drivers/dma/ti/k3-udma.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
> index b3f27b3f9209..b9e497e8134b 100644
> --- a/drivers/dma/ti/k3-udma.c
> +++ b/drivers/dma/ti/k3-udma.c
> @@ -1091,8 +1091,11 @@ static void udma_check_tx_completion(struct work_struct *work)
> u32 residue_diff;
> ktime_t time_diff;
> unsigned long delay;
> + unsigned long flags;
>
> while (1) {
> + spin_lock_irqsave(&uc->vc.lock, flags);
> +
> if (uc->desc) {
> /* Get previous residue and time stamp */
> residue_diff = uc->tx_drain.residue;
> @@ -1127,6 +1130,8 @@ static void udma_check_tx_completion(struct work_struct *work)
> break;
> }
>
> + spin_unlock_irqrestore(&uc->vc.lock, flags);
> +
> usleep_range(ktime_to_us(delay),
> ktime_to_us(delay) + 10);
> continue;
> @@ -1143,6 +1148,8 @@ static void udma_check_tx_completion(struct work_struct *work)
>
> break;
> }
> +
> + spin_unlock_irqrestore(&uc->vc.lock, flags);
> }
>
> static irqreturn_t udma_ring_irq_handler(int irq, void *data)
> --
> 2.48.0
>
--
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