From d98ddae85a4a57124f87960047b1b6419312147f Mon Sep 17 00:00:00 2001
From: Anilkumar Kolli <akolli@codeaurora.org>
Date: Thu, 26 Sep 2019 19:07:01 +0530
Subject: [PATCH] ath10k: fix backtrace on coredump
Git-commit: d98ddae85a4a57124f87960047b1b6419312147f
Patch-mainline: v5.5-rc1
References: git-fixes

In a multiradio board with one QCA9984 and one AR9987
after enabling the crashdump with module parameter
coredump_mask=7, below backtrace is seen.

Vmalloc: allocation failure: 0 bytes kworker/u4:0: page allocation failure: order:0, mode:0x80d2 CPU: 0 PID: 6 Comm: kworker/u4:0 Not tainted 3.14.77 #130 Workqueue: ath10k_wq ath10k_core_register_work [ath10k_core] (unwind_backtrace) from [<c021abf8>] (show_stack+0x10/0x14) (dump_stack+0x80/0xa0) (warn_alloc_failed+0xd0/0xfc) (__vmalloc_node_range+0x1b4/0x1d8) (__vmalloc_node+0x34/0x40) (vzalloc+0x24/0x30) (ath10k_coredump_register+0x6c/0x88 [ath10k_core]) (ath10k_core_register_work+0x350/0xb34 [ath10k_core]) (process_one_work+0x20c/0x32c) (worker_thread+0x228/0x360)

This is due to ath10k_hw_mem_layout is not defined for AR9987.
For coredump undefined hw ramdump_size is 0.
Check for the ramdump_size before allocation memory.

Tested on: AR9987, QCA9984
FW version: 10.4-3.9.0.2-00044

Signed-off-by: Anilkumar Kolli <akolli@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/ath/ath10k/coredump.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/net/wireless/ath/ath10k/coredump.c
+++ b/drivers/net/wireless/ath/ath10k/coredump.c
@@ -1105,9 +1105,11 @@ static struct ath10k_dump_file_data *ath
 		dump_tlv = (struct ath10k_tlv_dump_data *)(buf + sofar);
 		dump_tlv->type = cpu_to_le32(ATH10K_FW_CRASH_DUMP_RAM_DATA);
 		dump_tlv->tlv_len = cpu_to_le32(crash_data->ramdump_buf_len);
-		memcpy(dump_tlv->tlv_data, crash_data->ramdump_buf,
-		       crash_data->ramdump_buf_len);
-		sofar += sizeof(*dump_tlv) + crash_data->ramdump_buf_len;
+		if (crash_data->ramdump_buf_len) {
+			memcpy(dump_tlv->tlv_data, crash_data->ramdump_buf,
+			       crash_data->ramdump_buf_len);
+			sofar += sizeof(*dump_tlv) + crash_data->ramdump_buf_len;
+		}
 	}
 
 	spin_unlock_bh(&ar->data_lock);
@@ -1154,6 +1156,9 @@ int ath10k_coredump_register(struct ath1
 	if (test_bit(ATH10K_FW_CRASH_DUMP_RAM_DATA, &ath10k_coredump_mask)) {
 		crash_data->ramdump_buf_len = ath10k_coredump_get_ramdump_size(ar);
 
+		if (!crash_data->ramdump_buf_len)
+			return 0;
+
 		crash_data->ramdump_buf = vzalloc(crash_data->ramdump_buf_len);
 		if (!crash_data->ramdump_buf)
 			return -ENOMEM;