2021-10-11 20:55:58

by Ben Greear

Subject: [PATCH] mt76: mt7915: add debugging for MCU command timeouts.

From: Ben Greear <[email protected]>

Print information about whether the message is the first timeout,
and also print info if we manage to recover after a timeout.

Signed-off-by: Ben Greear <[email protected]>
---

NOTE: Not sure this is really something folks would want upstream, but
maybe it helps someone else trying to debug this driver.

drivers/net/wireless/mediatek/mt76/mt76.h | 2 ++
.../net/wireless/mediatek/mt76/mt7915/mcu.c | 35 +++++++++++++++++--
2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 2e1a1004ed30..3b64d288c7c2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -686,6 +686,8 @@ struct mt76_dev {
struct device *dev;

struct mt76_mcu mcu;
+ u32 first_failed_mcu_cmd; /* for debugging */
+ u32 last_successful_mcu_cmd; /* for debugging */

struct net_device napi_dev;
struct net_device tx_napi_dev;
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
index 51241b443cc5..e97cdeae785f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
@@ -323,14 +323,43 @@ mt7915_mcu_parse_response(struct mt76_dev *mdev, int cmd,
int ret = 0;

if (!skb) {
- dev_err(mdev->dev, "Message %08x (seq %d) timeout\n",
- cmd, seq);
+ const char* first = "Secondary";
+
+ if (!mdev->first_failed_mcu_cmd)
+ first = "Initial";
+
+ dev_err(mdev->dev, "MCU: %s Failure: Message %08x (cid %lx ext_cid: %lx seq %d) timeout. Last successful cmd: 0x%x\n",
+ first,
+ cmd, FIELD_GET(__MCU_CMD_FIELD_ID, cmd),
+ FIELD_GET(__MCU_CMD_FIELD_EXT_ID, cmd), seq,
+ mdev->last_successful_mcu_cmd);
+
+ if (!mdev->first_failed_mcu_cmd)
+ mdev->first_failed_mcu_cmd = cmd;
return -ETIMEDOUT;
}

+ mdev->last_successful_mcu_cmd = cmd;
+
+ if (mdev->first_failed_mcu_cmd) {
+ dev_err(mdev->dev, "MCU: First success after failure: Message %08x (cid %lx ext_cid: %lx seq %d)\n",
+ cmd, FIELD_GET(__MCU_CMD_FIELD_ID, cmd),
+ FIELD_GET(__MCU_CMD_FIELD_EXT_ID, cmd), seq);
+ mdev->first_failed_mcu_cmd = 0;
+ }
+ else {
+ // verbose debugging
+ //dev_err(mdev->dev, "MCU: OK response to message %08x (cid %lx ext_cid: %lx seq %d)\n",
+ // cmd, FIELD_GET(__MCU_CMD_FIELD_ID, cmd),
+ // FIELD_GET(__MCU_CMD_FIELD_EXT_ID, cmd), seq);
+ }
+
rxd = (struct mt7915_mcu_rxd *)skb->data;
- if (seq != rxd->seq)
+ if (seq != rxd->seq) {
+ dev_err(mdev->dev, "ERROR: MCU: Sequence mismatch in response, seq: %d rxd->seq: %d cmd: %0x\n",
+ seq, rxd->seq, cmd);
return -EAGAIN;
+ }

if (cmd == MCU_CMD(PATCH_SEM_CONTROL)) {
skb_pull(skb, sizeof(*rxd) - 4);
--
2.20.1

2021-10-12 05:15:18

by Kalle Valo

Subject: Re: [PATCH] mt76: mt7915: add debugging for MCU command timeouts.

[email protected] writes:

> From: Ben Greear <[email protected]>
>
> Print information about whether the message is the first timeout,
> and also print info if we manage to recover after a timeout.
>
> Signed-off-by: Ben Greear <[email protected]>
> ---
>
> NOTE: Not sure this is really something folks would want upstream, but
> maybe it helps someone else trying to debug this driver.

If the patch is not ready for upstream it's a good idea to mark it as
RFC, that way the maintainers can skip it automatically.

> + if (mdev->first_failed_mcu_cmd) {
> + dev_err(mdev->dev, "MCU: First success after failure: Message %08x (cid %lx ext_cid: %lx seq %d)\n",
> + cmd, FIELD_GET(__MCU_CMD_FIELD_ID, cmd),
> + FIELD_GET(__MCU_CMD_FIELD_EXT_ID, cmd), seq);
> + mdev->first_failed_mcu_cmd = 0;
> + }
> + else {
> + // verbose debugging
> + //dev_err(mdev->dev, "MCU: OK response to message %08x (cid %lx ext_cid: %lx seq %d)\n",
> + // cmd, FIELD_GET(__MCU_CMD_FIELD_ID, cmd),
> + // FIELD_GET(__MCU_CMD_FIELD_EXT_ID, cmd), seq);
> + }

No C++ comments and no commented out code, please.

--
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

2021-10-12 09:46:02

by Felix Fietkau

Subject: Re: [PATCH] mt76: mt7915: add debugging for MCU command timeouts.

On 2021-10-11 22:54, [email protected] wrote:
> From: Ben Greear <[email protected]>
>
> Print information about whether the message is the first timeout,
> and also print info if we manage to recover after a timeout.
>
> Signed-off-by: Ben Greear <[email protected]>
> ---
>
> NOTE: Not sure this is really something folks would want upstream, but
> maybe it helps someone else trying to debug this driver.
I think it would be much more useful to add tracepoints for tx/rx mcu
messages.

- Felix