| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | From e0d0cdff101b2f00ce1fd420522bd22bb6eebd9f Mon Sep 17 00:00:00 2001 |
| 2 | From: Robin Gong <yibin.gong@nxp.com> |
| 3 | Date: Wed, 13 Sep 2017 16:39:49 +0800 |
| 4 | Subject: [PATCH] MLK-16437: dma: fsl-edma-v3: fix kernel crash while edma |
| 5 | interrupt trigger after channel disabled |
| 6 | |
| 7 | edma interrupt may come after channel terminated, so should ignore |
| 8 | interrupts, else kernel crash as below since fsl_chan->edesc set |
| 9 | to NULL when terminate. |
| 10 | |
| 11 | 606.837306] Unable to handle kernel NULL pointer dereference at virtual address 00000060 |
| 12 | [ 606.845411] pgd = ffff000009295000 |
| 13 | [ 606.848814] [00000060] *pgd=00000008bfffe003[ 606.852906] , *pud=00000008bfffd003 |
| 14 | , *pmd=0000000000000000[ 606.858395] |
| 15 | [ 606.859885] Internal error: Oops: 96000006 1 PREEMPT SMP |
| 16 | [ 606.865460] Modules linked in: |
| 17 | [ 606.868522] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.11-03371-g9904ea0 #42 |
| 18 | [ 606.875832] Hardware name: Freescale i.MX8QXP LPDDR4 ARM2 (DT) |
| 19 | [ 606.881662] task: ffff000009120680 task.stack: ffff000009110000 |
| 20 | [ 606.887588] PC is at fsl_edma3_tx_handler+0x50/0x150 |
| 21 | |
| 22 | Signed-off-by: Robin Gong <yibin.gong@nxp.com> |
| 23 | Tested-by: Daniel Baluta <daniel.baluta@nxp.com> |
| 24 | (cherry picked from commit 625afad5a0900bc3e3288510f61647b1d891a5a4) |
| 25 | --- |
| 26 | drivers/dma/fsl-edma-v3.c | 5 +++++ |
| 27 | 1 file changed, 5 insertions(+) |
| 28 | |
| 29 | --- a/drivers/dma/fsl-edma-v3.c |
| 30 | +++ b/drivers/dma/fsl-edma-v3.c |
| 31 | @@ -689,6 +689,11 @@ static irqreturn_t fsl_edma3_tx_handler( |
| 32 | writel(1, base_addr + EDMA_CH_INT); |
| 33 | |
| 34 | spin_lock(&fsl_chan->vchan.lock); |
| 35 | + |
| 36 | + /* Ignore this interrupt since channel has been disabled already */ |
| 37 | + if (!fsl_chan->edesc) |
| 38 | + return IRQ_HANDLED; |
| 39 | + |
| 40 | if (!fsl_chan->edesc->iscyclic) { |
| 41 | fsl_edma3_get_realcnt(fsl_chan); |
| 42 | list_del(&fsl_chan->edesc->vdesc.node); |