From 2290ab43b9d8eafb8046387f10a8dfa2b030ba46 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Tue, 14 Oct 2025 12:53:44 +0100 Subject: [PATCH 1/4] firmware: arm_scmi: Account for failed debug initialization When the SCMI debug subsystem fails to initialize, the related debug root will be missing, and the underlying descriptor will be NULL. Handle this fault condition in the SCMI debug helpers that maintain metrics counters. Fixes: 0b3d48c4726e ("firmware: arm_scmi: Track basic SCMI communication debug metrics") Signed-off-by: Cristian Marussi Message-Id: <20251014115346.2391418-1-cristian.marussi@arm.com> Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/common.h | 24 ++++++++++++++-- drivers/firmware/arm_scmi/driver.c | 44 ++++++++++-------------------- 2 files changed, 35 insertions(+), 33 deletions(-) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 07b9e629276d..21c0b95027c6 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -309,10 +309,28 @@ enum debug_counters { SCMI_DEBUG_COUNTERS_LAST }; -static inline void scmi_inc_count(atomic_t *arr, int stat) +/** + * struct scmi_debug_info - Debug common info + * @top_dentry: A reference to the top debugfs dentry + * @name: Name of this SCMI instance + * @type: Type of this SCMI instance + * @is_atomic: Flag to state if the transport of this instance is atomic + * @counters: An array of atomic_c's used for tracking statistics (if enabled) + */ +struct scmi_debug_info { + struct dentry *top_dentry; + const char *name; + const char *type; + bool is_atomic; + atomic_t counters[SCMI_DEBUG_COUNTERS_LAST]; +}; + +static inline void scmi_inc_count(struct scmi_debug_info *dbg, int stat) { - if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) - atomic_inc(&arr[stat]); + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { + if (dbg) + atomic_inc(&dbg->counters[stat]); + } } static inline void scmi_dec_count(atomic_t *arr, int stat) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index bd56a877fdfc..56419285c0bf 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -115,22 +115,6 @@ struct scmi_protocol_instance { #define ph_to_pi(h) container_of(h, struct scmi_protocol_instance, ph) -/** - * struct scmi_debug_info - Debug common info - * @top_dentry: A reference to the top debugfs dentry - * @name: Name of this SCMI instance - * @type: Type of this SCMI instance - * @is_atomic: Flag to state if the transport of this instance is atomic - * @counters: An array of atomic_c's used for tracking statistics (if enabled) - */ -struct scmi_debug_info { - struct dentry *top_dentry; - const char *name; - const char *type; - bool is_atomic; - atomic_t counters[SCMI_DEBUG_COUNTERS_LAST]; -}; - /** * struct scmi_info - Structure representing a SCMI instance * @@ -1034,7 +1018,7 @@ scmi_xfer_command_acquire(struct scmi_chan_info *cinfo, u32 msg_hdr) spin_unlock_irqrestore(&minfo->xfer_lock, flags); scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNEXPECTED); - scmi_inc_count(info->dbg->counters, ERR_MSG_UNEXPECTED); + scmi_inc_count(info->dbg, ERR_MSG_UNEXPECTED); return xfer; } @@ -1062,7 +1046,7 @@ scmi_xfer_command_acquire(struct scmi_chan_info *cinfo, u32 msg_hdr) msg_type, xfer_id, msg_hdr, xfer->state); scmi_bad_message_trace(cinfo, msg_hdr, MSG_INVALID); - scmi_inc_count(info->dbg->counters, ERR_MSG_INVALID); + scmi_inc_count(info->dbg, ERR_MSG_INVALID); /* On error the refcount incremented above has to be dropped */ __scmi_xfer_put(minfo, xfer); @@ -1107,7 +1091,7 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo, PTR_ERR(xfer)); scmi_bad_message_trace(cinfo, msg_hdr, MSG_NOMEM); - scmi_inc_count(info->dbg->counters, ERR_MSG_NOMEM); + scmi_inc_count(info->dbg, ERR_MSG_NOMEM); scmi_clear_channel(info, cinfo); return; @@ -1123,7 +1107,7 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo, trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, xfer->hdr.id, "NOTI", xfer->hdr.seq, xfer->hdr.status, xfer->rx.buf, xfer->rx.len); - scmi_inc_count(info->dbg->counters, NOTIFICATION_OK); + scmi_inc_count(info->dbg, NOTIFICATION_OK); scmi_notify(cinfo->handle, xfer->hdr.protocol_id, xfer->hdr.id, xfer->rx.buf, xfer->rx.len, ts); @@ -1183,10 +1167,10 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) { scmi_clear_channel(info, cinfo); complete(xfer->async_done); - scmi_inc_count(info->dbg->counters, DELAYED_RESPONSE_OK); + scmi_inc_count(info->dbg, DELAYED_RESPONSE_OK); } else { complete(&xfer->done); - scmi_inc_count(info->dbg->counters, RESPONSE_OK); + scmi_inc_count(info->dbg, RESPONSE_OK); } if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { @@ -1296,7 +1280,7 @@ static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc, "timed out in resp(caller: %pS) - polling\n", (void *)_RET_IP_); ret = -ETIMEDOUT; - scmi_inc_count(info->dbg->counters, XFERS_RESPONSE_POLLED_TIMEOUT); + scmi_inc_count(info->dbg, XFERS_RESPONSE_POLLED_TIMEOUT); } } @@ -1321,7 +1305,7 @@ static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc, "RESP" : "resp", xfer->hdr.seq, xfer->hdr.status, xfer->rx.buf, xfer->rx.len); - scmi_inc_count(info->dbg->counters, RESPONSE_POLLED_OK); + scmi_inc_count(info->dbg, RESPONSE_POLLED_OK); if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { scmi_raw_message_report(info->raw, xfer, @@ -1336,7 +1320,7 @@ static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc, dev_err(dev, "timed out in resp(caller: %pS)\n", (void *)_RET_IP_); ret = -ETIMEDOUT; - scmi_inc_count(info->dbg->counters, XFERS_RESPONSE_TIMEOUT); + scmi_inc_count(info->dbg, XFERS_RESPONSE_TIMEOUT); } } @@ -1420,13 +1404,13 @@ static int do_xfer(const struct scmi_protocol_handle *ph, !is_transport_polling_capable(info->desc)) { dev_warn_once(dev, "Polling mode is not supported by transport.\n"); - scmi_inc_count(info->dbg->counters, SENT_FAIL_POLLING_UNSUPPORTED); + scmi_inc_count(info->dbg, SENT_FAIL_POLLING_UNSUPPORTED); return -EINVAL; } cinfo = idr_find(&info->tx_idr, pi->proto->id); if (unlikely(!cinfo)) { - scmi_inc_count(info->dbg->counters, SENT_FAIL_CHANNEL_NOT_FOUND); + scmi_inc_count(info->dbg, SENT_FAIL_CHANNEL_NOT_FOUND); return -EINVAL; } /* True ONLY if also supported by transport. */ @@ -1461,19 +1445,19 @@ static int do_xfer(const struct scmi_protocol_handle *ph, ret = info->desc->ops->send_message(cinfo, xfer); if (ret < 0) { dev_dbg(dev, "Failed to send message %d\n", ret); - scmi_inc_count(info->dbg->counters, SENT_FAIL); + scmi_inc_count(info->dbg, SENT_FAIL); return ret; } trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, xfer->hdr.id, "CMND", xfer->hdr.seq, xfer->hdr.status, xfer->tx.buf, xfer->tx.len); - scmi_inc_count(info->dbg->counters, SENT_OK); + scmi_inc_count(info->dbg, SENT_OK); ret = scmi_wait_for_message_response(cinfo, xfer); if (!ret && xfer->hdr.status) { ret = scmi_to_linux_errno(xfer->hdr.status); - scmi_inc_count(info->dbg->counters, ERR_PROTOCOL); + scmi_inc_count(info->dbg, ERR_PROTOCOL); } if (info->desc->ops->mark_txdone) From 289ce7e9a5e1a52ac7e522a3e389dc16be08d7a4 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Tue, 14 Oct 2025 12:53:45 +0100 Subject: [PATCH 2/4] include: trace: Fix inflight count helper on failed initialization Add a check to the scmi_inflight_count() helper to handle the case when the SCMI debug subsystem fails to initialize. Fixes: f8e656382b4a ("include: trace: Add tracepoint support for inflight xfer count") Signed-off-by: Cristian Marussi Message-Id: <20251014115346.2391418-2-cristian.marussi@arm.com> Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/common.h | 8 +++++--- drivers/firmware/arm_scmi/driver.c | 7 +++++-- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 21c0b95027c6..7c35c95fddba 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -333,10 +333,12 @@ static inline void scmi_inc_count(struct scmi_debug_info *dbg, int stat) } } -static inline void scmi_dec_count(atomic_t *arr, int stat) +static inline void scmi_dec_count(struct scmi_debug_info *dbg, int stat) { - if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) - atomic_dec(&arr[stat]); + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { + if (dbg) + atomic_dec(&dbg->counters[stat]); + } } enum scmi_bad_msg { diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 56419285c0bf..1cd15412024c 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -594,7 +594,7 @@ scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer, /* Set in-flight */ set_bit(xfer->hdr.seq, minfo->xfer_alloc_table); hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq); - scmi_inc_count(info->dbg->counters, XFERS_INFLIGHT); + scmi_inc_count(info->dbg, XFERS_INFLIGHT); xfer->pending = true; } @@ -803,7 +803,7 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) hash_del(&xfer->node); xfer->pending = false; - scmi_dec_count(info->dbg->counters, XFERS_INFLIGHT); + scmi_dec_count(info->dbg, XFERS_INFLIGHT); } hlist_add_head(&xfer->node, &minfo->free_xfers); } @@ -3407,6 +3407,9 @@ int scmi_inflight_count(const struct scmi_handle *handle) if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { struct scmi_info *info = handle_to_scmi_info(handle); + if (!info->dbg) + return 0; + return atomic_read(&info->dbg->counters[XFERS_INFLIGHT]); } else { return 0; From 092b9e2ce6dd63d2f36822751a51957412706986 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Tue, 14 Oct 2025 12:53:46 +0100 Subject: [PATCH 3/4] firmware: arm_scmi: Skip RAW initialization on failure Avoid attempting to initialize RAW mode when the debug subsystem itself has failed to initialize, since doing so is pointless and emits misleading error messages. Signed-off-by: Cristian Marussi Message-Id: <20251014115346.2391418-3-cristian.marussi@arm.com> Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 1cd15412024c..eb46694cb14b 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -3028,9 +3028,6 @@ static int scmi_debugfs_raw_mode_setup(struct scmi_info *info) u8 channels[SCMI_MAX_CHANNELS] = {}; DECLARE_BITMAP(protos, SCMI_MAX_CHANNELS) = {}; - if (!info->dbg) - return -EINVAL; - /* Enumerate all channels to collect their ids */ idr_for_each_entry(&info->tx_idr, cinfo, id) { /* @@ -3202,7 +3199,7 @@ static int scmi_probe(struct platform_device *pdev) if (!info->dbg) dev_warn(dev, "Failed to setup SCMI debugfs.\n"); - if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { + if (info->dbg && IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { ret = scmi_debugfs_raw_mode_setup(info); if (!coex) { if (ret) From 20b93a0088a595bceed4a026d527cbbac4e876c5 Mon Sep 17 00:00:00 2001 From: Artem Shimko Date: Wed, 8 Oct 2025 12:10:57 +0300 Subject: [PATCH 4/4] firmware: arm_scmi: Fix premature SCMI_XFER_FLAG_IS_RAW clearing in raw mode The SCMI_XFER_FLAG_IS_RAW flag was being cleared prematurely in scmi_xfer_raw_put() before the transfer completion was properly acknowledged by the raw message handlers. Move the clearing of SCMI_XFER_FLAG_IS_RAW and SCMI_XFER_FLAG_CHAN_SET from scmi_xfer_raw_put() to __scmi_xfer_put() to ensure the flags remain set throughout the entire raw message processing pipeline until the transfer is returned to the free pool. Fixes: 3095a3e25d8f ("firmware: arm_scmi: Add xfer helpers to provide raw access") Suggested-by: Cristian Marussi Signed-off-by: Artem Shimko Reviewed-by: Cristian Marussi Message-Id: <20251008091057.1969260-1-a.shimko.dev@gmail.com> Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index eb46694cb14b..5caa9191a8d1 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -805,6 +805,7 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) scmi_dec_count(info->dbg, XFERS_INFLIGHT); } + xfer->flags = 0; hlist_add_head(&xfer->node, &minfo->free_xfers); } spin_unlock_irqrestore(&minfo->xfer_lock, flags); @@ -823,8 +824,6 @@ void scmi_xfer_raw_put(const struct scmi_handle *handle, struct scmi_xfer *xfer) { struct scmi_info *info = handle_to_scmi_info(handle); - xfer->flags &= ~SCMI_XFER_FLAG_IS_RAW; - xfer->flags &= ~SCMI_XFER_FLAG_CHAN_SET; return __scmi_xfer_put(&info->tx_minfo, xfer); }