Re: [PATCH 1/2] dt-bindings: net: wireless: ath10k: add qcom,no-msa-ready-indicator prop

[Marc Gonzalez <mgonzalez@freebox.fr>]

On 01/03/2024 09:10, Kalle Valo wrote:

> Marc Gonzalez wrote:
> 
>> Kalle Valo wrote:
>> 
>>> Here's one example where in ath10k we use a feature bit as a workaround:
>>>
>>> 	/* Don't trust error code from otp.bin */
>>> 	ATH10K_FW_FEATURE_IGNORE_OTP_RESULT = 7,
>>>
>>>         ....
>>>
>>> 	if (!(skip_otp || test_bit(ATH10K_FW_FEATURE_IGNORE_OTP_RESULT,
>>> 				   ar->running_fw->fw_file.fw_features)) &&
>>> 	    result != 0) {
>>> 		ath10k_err(ar, "otp calibration failed: %d", result);
>>> 		return -EINVAL;
>>> 	}
>>>
>>> BTW for modifying firmware-N.bin files we have a script here:
>>>
>>> https://github.com/qca/qca-swiss-army-knife/blob/master/tools/scripts/ath10k/ath10k-fwencoder
>>
>> If I understand correctly, you are saying that there is
>> (maybe... probably) a bug in the FW, so it makes sense to
>> tag that specific FW file with a special bit which the kernel
>> will interpret as "this FW is broken in a specific way;
>> and here's how to work around the issue."
>>
>> So this bit would serve the same purpose as my proposed
>> "qcom,no-msa-ready-indicator" bit (that bit existed instead
>> in my board's device tree).
>>
>> The problem I see is that the firmware files are signed.
>> Thus, changing a single bit breaks the verification...
>> UNLESS the FW format allows for a signed section ALONG-SIDE
>> an unsigned section?
> 
> firmware-N.bin is ath10k specific container file format and we (the
> Linux community) have full access to it using ath10k-fwencoder, there's
> no signing or anything like that. One of the major reasons why it was
> designed was to handle differences between firmware branches, just like
> in this case.
> 
> Of course plan A should be to fix the firmware but if that doesn't work
> out then plan B could be using the feature bit in firmware-N.bin.
> 
> BTW related to this Dmitry is extending firmware-N.bin handling for
> WCN3990, you will most likely need to use that:
> 
> https://patchwork.kernel.org/project/linux-wireless/cover/20240130-wcn3990-firmware-path-v1-0-826b93202964@linaro.org/


If I understand correctly (happy to have anyone correct any
misunderstandings), if the FW cannot be fixed (for any reason),
then we would have to do something like this:


diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 0032f8aa892ff..c8778ebe922af 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -769,6 +769,7 @@ static const char *const ath10k_core_fw_feature_str[] = {
 	[ATH10K_FW_FEATURE_SINGLE_CHAN_INFO_PER_CHANNEL] = "single-chan-info-per-channel",
 	[ATH10K_FW_FEATURE_PEER_FIXED_RATE] = "peer-fixed-rate",
 	[ATH10K_FW_FEATURE_IRAM_RECOVERY] = "iram-recovery",
+	[ATH10K_FW_FEATURE_NO_MSA_READY] = "no-msa-ready-indicator",
 };
 
 static unsigned int ath10k_core_get_fw_feature_str(char *buf,
@@ -2941,6 +2942,9 @@ int ath10k_core_start(struct ath10k *ar, enum ath10k_firmware_mode mode,
 
 	ar->running_fw = fw;
 
+	if (test_bit(ATH10K_FW_FEATURE_NO_MSA_READY, fw->fw_file.fw_features))
+		ar->fake_msa_ready = true;
+
 	if (!test_bit(ATH10K_FW_FEATURE_NON_BMI,
 		      ar->running_fw->fw_file.fw_features)) {
 		ath10k_bmi_start(ar);
diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index c110d15528bd0..ce71097b97a1d 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -835,6 +835,9 @@ enum ath10k_fw_features {
 	/* Firmware support IRAM recovery */
 	ATH10K_FW_FEATURE_IRAM_RECOVERY = 22,
 
+	/* Firware does not send MSA_READY indicator */
+	ATH10K_FW_FEATURE_NO_MSA_READY = 23,
+
 	/* keep last */
 	ATH10K_FW_FEATURE_COUNT,
 };
@@ -1151,6 +1154,9 @@ struct ath10k {
 	u8 cfg_tx_chainmask;
 	u8 cfg_rx_chainmask;
 
+	/* FW does not send MSA_READY indicator. Fake it */
+	bool fake_msa_ready; /* bool or u8? or s8? or bitfield? */
+
 	struct completion install_key_done;
 
 	int last_wmi_vdev_start_status;
diff --git a/drivers/net/wireless/ath/ath10k/qmi.c b/drivers/net/wireless/ath/ath10k/qmi.c
index 38e939f572a9e..0776e79b25f3a 100644
--- a/drivers/net/wireless/ath/ath10k/qmi.c
+++ b/drivers/net/wireless/ath/ath10k/qmi.c
@@ -1040,6 +1040,8 @@ static void ath10k_qmi_driver_event_work(struct work_struct *work)
 		switch (event->type) {
 		case ATH10K_QMI_EVENT_SERVER_ARRIVE:
 			ath10k_qmi_event_server_arrive(qmi);
+			if (ar->fake_msa_ready)
+				ath10k_qmi_event_msa_ready(qmi);
 			break;
 		case ATH10K_QMI_EVENT_SERVER_EXIT:
 			ath10k_qmi_event_server_exit(qmi);


-- 
Regards