From: Kalle Valo <kvalo@codeaurora.org>
To: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: linux-wireless@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v2] iwlwifi: mvm: don't send the IWL_MVM_RXQ_NSSN_SYNC notif to Rx queues
Date: Mon, 2 Dec 2019 14:43:53 +0000 [thread overview]
Message-ID: <0101016ec711594b-f0e8e2cc-29f2-45ad-aa61-abd47dfc511c-000000@us-west-2.amazonses.com> (raw)
In-Reply-To: <20191121184530.5393-1-emmanuel.grumbach@intel.com> (Emmanuel Grumbach's message of "Thu, 21 Nov 2019 20:45:30 +0200")
Emmanuel Grumbach <emmanuel.grumbach@intel.com> writes:
> The purpose of this was to keep all the queues updated with
> the Rx sequence numbers because unlikely yet possible
> situations where queues can't understand if a specific
> packet needs to be dropped or not.
>
> Unfortunately, it was reported that this caused issues in
> our DMA engine. We don't fully understand how this is related,
> but this is being currently debugged. For now, just don't send
> this notification to the Rx queues. This de-facto reverts my
> commit 3c514bf831ac12356b695ff054bef641b9e99593:
>
> iwlwifi: mvm: add a loose synchronization of the NSSN across Rx queues
>
> This issue was reported here:
> https://bugzilla.kernel.org/show_bug.cgi?id=204873
> https://bugzilla.kernel.org/show_bug.cgi?id=205001
> and others maybe.
>
> Fixes: 3c514bf831ac ("iwlwifi: mvm: add a loose synchronization of the NSSN across Rx queues")
> CC: <stable@vger.kernel.org> # 5.3+
> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
> ---
> v2: avoid the unused variable warning
> ---
> drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c | 22 ++++++++++++-------
> 1 file changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
> index 75a7af5ad7b2..392bfa4b496c 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
> @@ -514,14 +514,20 @@ static bool iwl_mvm_is_sn_less(u16 sn1, u16 sn2, u16 buffer_size)
>
> static void iwl_mvm_sync_nssn(struct iwl_mvm *mvm, u8 baid, u16 nssn)
> {
> - struct iwl_mvm_rss_sync_notif notif = {
> - .metadata.type = IWL_MVM_RXQ_NSSN_SYNC,
> - .metadata.sync = 0,
> - .nssn_sync.baid = baid,
> - .nssn_sync.nssn = nssn,
> - };
> -
> - iwl_mvm_sync_rx_queues_internal(mvm, (void *)¬if, sizeof(notif));
> + /*
> + * This allow to synchronize the queues, but it has been reported
> + * to cause FH issues. Don't send the notification for now.
> + *
> + * struct iwl_mvm_rss_sync_notif notif = {
> + * .metadata.type = IWL_MVM_RXQ_NSSN_SYNC,
> + * .metadata.sync = 0,
> + * .nssn_sync.baid = baid,
> + * .nssn_sync.nssn = nssn,
> + * };
> + *
> + *
> + * iwl_mvm_sync_rx_queues_internal(mvm, (void *)¬if, sizeof(notif));
> + */
Please don't comment out code, instead remove entirely. You can find the
old code from the git history anyway.
--
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
next prev parent reply other threads:[~2019-12-02 14:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-20 13:26 [PATCH] iwlwifi: mvm: don't send the IWL_MVM_RXQ_NSSN_SYNC notif to Rx queues Emmanuel Grumbach
2019-11-21 18:32 ` Kalle Valo
2019-11-21 18:45 ` [PATCH v2] " Emmanuel Grumbach
2019-12-02 14:43 ` Kalle Valo [this message]
2019-12-03 7:58 ` [PATCH v3] " Emmanuel Grumbach
2019-12-03 8:08 ` [PATCH v4] " Emmanuel Grumbach
2019-12-03 9:03 ` Kalle Valo
2019-12-03 9:22 ` Luca Coelho
2020-01-17 14:32 ` Kalle Valo
2020-01-22 17:26 ` Kalle Valo
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