ath11k: Use GFP_ATOMIC instead of GFP_KERNEL in ath11k_dp_htt_get_ppdu_desc

With SLUB DEBUG CONFIG below crash is seen as kmem_cache_alloc
is being called in non-atomic context.

To fix this issue, use GFP_ATOMIC instead of GFP_KERNEL kzalloc.

[  357.217088] BUG: sleeping function called from invalid context at mm/slab.h:498
[  357.217091] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/0
[  357.217092] INFO: lockdep is turned off.
[  357.217095] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W         5.9.0-rc5-wt-ath+ #196
[  357.217096] Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0049.2018.0801.1601 08/01/2018
[  357.217097] Call Trace:
[  357.217098]  <IRQ>
[  357.217107]  ? ath11k_dp_htt_get_ppdu_desc+0xa9/0x170 [ath11k]
[  357.217110]  dump_stack+0x77/0xa0
[  357.217113]  ___might_sleep.cold+0xa6/0xb6
[  357.217116]  kmem_cache_alloc_trace+0x1f2/0x270
[  357.217122]  ath11k_dp_htt_get_ppdu_desc+0xa9/0x170 [ath11k]
[  357.217129]  ath11k_htt_pull_ppdu_stats.isra.0+0x96/0x270 [ath11k]
[  357.217135]  ath11k_dp_htt_htc_t2h_msg_handler+0xe7/0x1d0 [ath11k]
[  357.217137]  ? trace_hardirqs_on+0x1c/0x100
[  357.217143]  ath11k_htc_rx_completion_handler+0x207/0x370 [ath11k]
[  357.217149]  ath11k_ce_recv_process_cb+0x15e/0x1e0 [ath11k]
[  357.217151]  ? handle_irq_event+0x70/0xa8
[  357.217154]  ath11k_pci_ce_tasklet+0x10/0x30 [ath11k_pci]
[  357.217157]  tasklet_action_common.constprop.0+0xd4/0xf0
[  357.217160]  __do_softirq+0xc9/0x482
[  357.217162]  asm_call_on_stack+0x12/0x20
[  357.217163]  </IRQ>
[  357.217166]  do_softirq_own_stack+0x49/0x60
[  357.217167]  irq_exit_rcu+0x9a/0xd0
[  357.217169]  common_interrupt+0xa1/0x190
[  357.217171]  asm_common_interrupt+0x1e/0x40
[  357.217173] RIP: 0010:cpu_idle_poll.isra.0+0x2e/0x60
[  357.217175] Code: 8b 35 26 27 74 69 e8 11 c8 3d ff e8 bc fa 42 ff e8 e7 9f 4a ff fb 65 48 8b 1c 25 80 90 01 00 48 8b 03 a8 08 74 0b eb 1c f3 90 <48> 8b 03 a8 08 75 13 8b 0
[  357.217177] RSP: 0018:ffffffff97403ee0 EFLAGS: 00000202
[  357.217178] RAX: 0000000000000001 RBX: ffffffff9742b8c0 RCX: 0000000000b890ca
[  357.217180] RDX: 0000000000b890ca RSI: 0000000000000001 RDI: ffffffff968d0c49
[  357.217181] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
[  357.217182] R10: ffffffff9742b8c0 R11: 0000000000000046 R12: 0000000000000000
[  357.217183] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000066fdf520
[  357.217186]  ? cpu_idle_poll.isra.0+0x19/0x60
[  357.217189]  do_idle+0x5f/0xe0
[  357.217191]  cpu_startup_entry+0x14/0x20
[  357.217193]  start_kernel+0x443/0x464
[  357.217196]  secondary_startup_64+0xa4/0xb0

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1601399736-3210-8-git-send-email-kvalo@codeaurora.org

drivers/net/wireless/ath/ath11k/dp_rx.c

@@ -1478,7 +1478,7 @@ struct htt_ppdu_stats_info *ath11k_dp_htt_get_ppdu_desc(struct ath11k *ar,
 	}
 	spin_unlock_bh(&ar->data_lock);
 
-	ppdu_info = kzalloc(sizeof(*ppdu_info), GFP_KERNEL);
+	ppdu_info = kzalloc(sizeof(*ppdu_info), GFP_ATOMIC);
 	if (!ppdu_info)
 		return NULL;