[PATCH] dma: zynqmp_dma: Initialize descriptor list after freeing during reset

Rafał Hibner
2020-04-28T14:34:21Z

List elements are not formally removed from list therefore
list head is not initialized during zynqmp_dma_reset.

Signed-off-by: Rafal Hibner <rafal.hibner@secom.com.pl>

This BUG causes kernel panic when transaction is unsuccessful:
------------[ cut here ]------------
[ 62.710730] list_add corruption. prev->next should be next (ffffffc07d308040), but was dead000000000100. (prev=ffffffc0540b40b8).
[ 62.727960] WARNING: CPU: 0 PID: 1845 at /home/rafalh11/zynq_proj/zynq_platform/KERNEL/linux-xlnx/lib/list_debug.c:28 __list_add_valid+0x74/0xa0
[ 62.746374] Modules linked in: secom_mx_rpmsg(O) rpmsg_char secom_mx_retune(O) ad9680(O) ad5686_spi(O) ad5686(O) ad7298(O) ltc5594(O) lmx2594(O) ad8366(O) secom_mx(O) axi_jesd204_rx(O) axi_adxcvr(O) xilinx_transceiver(O) cf_axi_adc_core(O) hmc7044(O)
[ 62.768546] CPU: 0 PID: 1845 Comm: mx Tainted: G O 4.19.0 #10
[ 62.775582] Hardware name: xlnx,zynqmp (DT)
[ 62.779750] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 62.784524] pc : __list_add_valid+0x74/0xa0
[ 62.788690] lr : __list_add_valid+0x74/0xa0
[ 62.792855] sp : ffffff8008003da0
[ 62.796154] x29: ffffff8008003da0 x28: 0000000000000020
[ 62.801457] x27: 0000000000000000 x26: dead000000000100
[ 62.806760] x25: ffffffc07d308040 x24: ffffffc0540b40a0
[ 62.812064] x23: ffffffc07d308018 x22: 0000000000000000
[ 62.817359] x21: ffffffc07d308018 x20: ffffffc0540b40b8
[ 62.822654] x19: ffffffc0540b40b8 x18: ffffffffffffffff
[ 62.827957] x17: 0000000000000000 x16: 0000000000000000
[ 62.833252] x15: ffffff8008f88648 x14: 3034303830336437
[ 62.838546] x13: ffffff8008f88670 x12: ffffff80085d0ec0
[ 62.843841] x11: ffffff8008f65018 x10: 0000000000000006
[ 62.849136] x9 : 657270202e6e6f69 x8 : 3462303435306366
[ 62.854431] x7 : 66666666663d7665 x6 : 00000000000001a2
[ 62.859726] x5 : 0000000000000064 x4 : 0000000000000000
[ 62.865020] x3 : 0000000000000000 x2 : ffffffffffffffff
[ 62.870315] x1 : 0cbee765ba0ec900 x0 : 0000000000000000
[ 62.875611] Call trace:
[ 62.878042] __list_add_valid+0x74/0xa0
[ 62.881864] zynqmp_dma_free_descriptor+0x48/0x100
[ 62.886644] zynqmp_dma_chan_desc_cleanup+0xb4/0xf8
[ 62.891505] zynqmp_dma_do_tasklet+0x68/0x110
[ 62.895847] tasklet_action_common.isra.3+0x7c/0x168
[ 62.900801] tasklet_action+0x24/0x30
[ 62.904447] __do_softirq+0x10c/0x200
[ 62.908092] irq_exit+0xac/0xc0
[ 62.911219] __handle_domain_irq+0x60/0xb0
[ 62.915305] gic_handle_irq+0x64/0xc0
[ 62.918951] el1_irq+0xb0/0x140
[ 62.922078] schedule_timeout+0x218/0x3a0
[ 62.926077] wait_for_common+0x170/0x268
[ 62.929983] wait_for_completion_timeout+0x10/0x18
[ 62.934761] ioctl+0x64/0x270 [secom_mx_retune]
[ 62.939281] do_vfs_ioctl+0xb8/0x900
[ 62.942838] ksys_ioctl+0x44/0x90
[ 62.946137] __arm64_sys_ioctl+0x1c/0x28
[ 62.950044] el0_svc_common+0x60/0xe8
[ 62.953689] el0_svc_handler+0x6c/0x88
[ 62.957421] el0_svc+0x8/0xc
[ 62.960284] ---[ end trace 91b4fdfe685446c4 ]---
[ 62.964934] ------------[ cut here ]------------

---
drivers/dma/xilinx/zynqmp_dma.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index 931e41a72..a2b0be07e 100644
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -453,6 +453,7 @@ static void zynqmp_dma_free_desc_list(struct zynqmp_dma_chan *chan,

list_for_each_entry_safe(desc, next, list, node)
zynqmp_dma_free_descriptor(chan, desc);
+ INIT_LIST_HEAD(list);
}

/**
--
2.20.1