[RFC 4/4] ath10k: Dump exception stack contents on firmware crash.

[greearb at candelatech.com]

From: Ben Greear <greearb at candelatech.com>

Firmware developers can decode this and maybe figure out
why the firmware crashed.

Signed-off-by: Ben Greear <greearb at candelatech.com>
---
 drivers/net/wireless/ath/ath10k/core.h  |  2 ++
 drivers/net/wireless/ath/ath10k/debug.c | 10 +++++++++-
 drivers/net/wireless/ath/ath10k/pci.c   | 11 ++++++++++-
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index b331942..f389bde 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -350,6 +350,7 @@ enum ath10k_fw_error_dump_type {
 	ATH10K_FW_ERROR_DUMP_DBGLOG = 0,
 	ATH10K_FW_ERROR_DUMP_REGDUMP = 1,
 	ATH10K_FW_ERROR_DUMP_STACK = 2,
+	ATH10K_FW_ERROR_DUMP_EXC_STACK = 3,
 
 	ATH10K_FW_ERROR_DUMP_MAX,
 };
@@ -531,6 +532,7 @@ struct ath10k {
 	struct ath10k_dbglog_entry_storage dbglog_entry_data;
 	u32 reg_dump_values[REG_DUMP_COUNT_QCA988X];
 	unsigned char stack_buf[ATH10K_FW_STACK_SIZE];
+	unsigned char exc_stack_buf[ATH10K_FW_STACK_SIZE];
 
 #ifdef CONFIG_ATH10K_DEBUGFS
 	struct ath10k_debug debug;
diff --git a/drivers/net/wireless/ath/ath10k/debug.c b/drivers/net/wireless/ath/ath10k/debug.c
index 9c9456d..0c12c9d 100644
--- a/drivers/net/wireless/ath/ath10k/debug.c
+++ b/drivers/net/wireless/ath/ath10k/debug.c
@@ -600,6 +600,7 @@ static struct ath10k_dump_file_data *ath10k_build_dump_file(struct ath10k *ar)
 {
 	unsigned int len = (sizeof(ar->dbglog_entry_data)
 			    + sizeof(ar->stack_buf)
+			    + sizeof(ar->exc_stack_buf)
 			    + sizeof(ar->reg_dump_values));
 	unsigned int sofar = 0;
 	char *buf;
@@ -611,7 +612,7 @@ static struct ath10k_dump_file_data *ath10k_build_dump_file(struct ath10k *ar)
 	sofar += hdr_len;
 
 	/* So we can add headers to the data dump */
-	len += 3 * sizeof(*dump_tlv);
+	len += 4 * sizeof(*dump_tlv);
 
 	/* This is going to get big when we start dumping FW RAM and such,
 	 * so go ahead and use vmalloc.
@@ -645,6 +646,13 @@ static struct ath10k_dump_file_data *ath10k_build_dump_file(struct ath10k *ar)
 	memcpy(dump_tlv->tlv_data, &ar->stack_buf, dump_tlv->tlv_len);
 	sofar += sizeof(*dump_tlv) + dump_tlv->tlv_len;
 
+	/* Gather firmware exception (irq) stack dump */
+	dump_tlv = (struct ath10k_tlv_dump_data *)(buf + sofar);
+	dump_tlv->type = ATH10K_FW_ERROR_DUMP_EXC_STACK;
+	dump_tlv->tlv_len = sizeof(ar->exc_stack_buf);
+	memcpy(dump_tlv->tlv_data, &ar->exc_stack_buf, dump_tlv->tlv_len);
+	sofar += sizeof(*dump_tlv) + dump_tlv->tlv_len;
+
 	WARN_ON(sofar != len);
 	return dump_data;
 }
diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
index 821a216..bf258e1 100644
--- a/drivers/net/wireless/ath/ath10k/pci.c
+++ b/drivers/net/wireless/ath/ath10k/pci.c
@@ -864,6 +864,13 @@ static void ath10k_save_firmware_stack(struct ath10k *ar)
 					ar->stack_buf, HI_ITEM(hi_stack));
 }
 
+/* Save the firmware exception stack */
+static void ath10k_save_firmware_exc_stack(struct ath10k *ar)
+{
+	ath10k_save_firmware_mem_helper(ar, ATH10K_FW_STACK_SIZE,
+					ar->exc_stack_buf,
+					HI_ITEM(hi_err_stack));
+}
 
 static void ath10k_pci_hif_dump_area(struct ath10k *ar)
 {
@@ -909,8 +916,10 @@ static void ath10k_pci_hif_dump_area(struct ath10k *ar)
 			   reg_dump_values[i + 2],
 			   reg_dump_values[i + 3]);
 
-	if (!ar->crashed_since_read)
+	if (!ar->crashed_since_read) {
 		ath10k_save_firmware_stack(ar);
+		ath10k_save_firmware_exc_stack(ar);
+	}
 
 	/* Dump the debug logs on the target */
 	host_addr = host_interest_item_address(HI_ITEM(hi_dbglog_hdr));
-- 
1.7.11.7