Building the driver as a module and when removing the already inserted module gives below: [ 1389.392788] Unable to handle kernel paging request at virtual address ffffffbdc000001c [ 1389.421321] pgd = ffffffc02fa87000 [ 1389.447899] [ffffffbdc000001c] *pgd=0000000000000000, *pud=0000000000000000 [ 1389.460142] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 1389.466963] Modules linked in: qcom_bam_dma(-) [ 1389.486608] CPU: 2 PID: 2442 Comm: rmmod Not tainted 4.2.0+ #407 [ 1389.493885] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) [ 1389.501196] task: ffffffc035bae2c0 ti: ffffffc0368a8000 task.ti: ffffffc0368a8000 [ 1389.508566] PC is at __free_pages+0xc/0x40 [ 1389.515893] LR is at free_pages.part.93+0x30/0x38 [ 1389.523141] pc : [<ffffffc00016180c>] lr : [<ffffffc00016197c>] pstate: 80000145 [ 1389.530602] sp : ffffffc0368abc20 [ 1389.537931] x29: ffffffc0368abc20 x28: ffffffc0368a8000 [ 1389.549153] x27: 0000000000000000 x26: 0000000000000000 [ 1389.560412] x25: ffffffc000cb2000 x24: 0000000000000170 [ 1389.571530] x23: 0000000000000004 x22: ffffffc036bc5010 [ 1389.582721] x21: ffffffc036bc5010 x20: 0000000000000000 [ 1389.593981] x19: 0000000000000002 x18: 0000007fcbc8e8b0 [ 1389.605301] x17: 0000007f9b8226ec x16: ffffffc0002089e8 [ 1389.616647] x15: 0000007f9b8a0588 x14: 0ffffffffffffffc [ 1389.628039] x13: 0000000000000030 x12: 0000000000000000 [ 1389.639436] x11: 0000000000000008 x10: ffffffc000ecc000 [ 1389.650872] x9 : ffffffc035bae2c0 x8 : ffffffc035bae9a8 [ 1389.662367] x7 : ffffffc035bae9a0 x6 : 0000000000000000 [ 1389.673906] x5 : ffffffbdc000001c x4 : 0000000080000000 [ 1389.685475] x3 : ffffffbdc0000000 x2 : 0000004080000000 [ 1389.697049] x1 : 0000000000000003 x0 : ffffffbdc0000000 The memory has been already freed by bam_free_chan() so fix this by skiping already freed memory. Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx> --- drivers/dma/qcom_bam_dma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dma/qcom_bam_dma.c b/drivers/dma/qcom_bam_dma.c index 5a250cdc8376..dc9da477eb69 100644 --- a/drivers/dma/qcom_bam_dma.c +++ b/drivers/dma/qcom_bam_dma.c @@ -1231,6 +1231,9 @@ static int bam_dma_remove(struct platform_device *pdev) bam_dma_terminate_all(&bdev->channels[i].vc.chan); tasklet_kill(&bdev->channels[i].vc.task); + if (!bdev->channels[i].fifo_virt) + continue; + dma_free_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE, bdev->channels[i].fifo_virt, bdev->channels[i].fifo_phys); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
