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