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From:   Rameshkumar Sundaram <quic_ramess@quicinc.com>
To:     <ath11k@lists.infradead.org>
CC:     <linux-wireless@vger.kernel.org>,
        Rameshkumar Sundaram <quic_ramess@quicinc.com>
Subject: [PATCH] ath11k: Invalidate cached reo ring entry before accessing it
Date:   Wed, 16 Feb 2022 13:57:51 +0530
Message-ID: <1645000071-25832-1-git-send-email-quic_ramess@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

REO2SW ring descriptor is currently allocated in cacheable memory.
While reaping reo ring entries on second trial after updating head
pointer, first entry needs to be invalidated before accessing it.

Move the try_again: label above  ath11k_hal_srng_access_begin()
so that first entry will be invalidated and prefetched.

Tested on: QCN9074 hw1.0 PCI WLAN.HK.2.5.0.1-01100-QCAHKSWPL_SILICONZ-1

Fixes: 6452f0a3d565 ("ath11k: allocate dst ring descriptors from cacheable memory")
Signed-off-by: Rameshkumar Sundaram <quic_ramess@quicinc.com>
---
 drivers/net/wireless/ath/ath11k/dp_rx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index c212a78..e432f8d 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -2642,9 +2642,9 @@ int ath11k_dp_process_rx(struct ath11k_base *ab, int ring_id,
 
 	spin_lock_bh(&srng->lock);
 
+try_again:
 	ath11k_hal_srng_access_begin(ab, srng);
 
-try_again:
 	while (likely(desc =
 	      (struct hal_reo_dest_ring *)ath11k_hal_srng_dst_get_next_entry(ab,
 									     srng))) {
-- 
2.7.4