From:   Alex Elder <elder@linaro.org>
To:     davem@davemloft.net, kuba@kernel.org
Cc:     pkurapat@codeaurora.org, avuyyuru@codeaurora.org,
        bjorn.andersson@linaro.org, cpratapa@codeaurora.org,
        subashab@codeaurora.org, evgreen@chromium.org, elder@kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net 1/2] net: ipa: HOLB register sometimes must be written twice
Date:   Fri, 12 Nov 2021 16:22:09 -0600
Message-Id: <20211112222210.224057-2-elder@linaro.org>
In-Reply-To: <20211112222210.224057-1-elder@linaro.org>
References: <20211112222210.224057-1-elder@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Starting with IPA v4.5, the HOL_BLOCK_EN register must be written
twice when enabling head-of-line blocking avoidance.

Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints")
Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_endpoint.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index 5528d97110d56..006da4642a0ba 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -868,6 +868,9 @@ ipa_endpoint_init_hol_block_enable(struct ipa_endpoint *endpoint, bool enable)
 	val = enable ? HOL_BLOCK_EN_FMASK : 0;
 	offset = IPA_REG_ENDP_INIT_HOL_BLOCK_EN_N_OFFSET(endpoint_id);
 	iowrite32(val, endpoint->ipa->reg_virt + offset);
+	/* When enabling, the register must be written twice for IPA v4.5+ */
+	if (enable && endpoint->ipa->version >= IPA_VERSION_4_5)
+		iowrite32(val, endpoint->ipa->reg_virt + offset);
 }
 
 void ipa_endpoint_modem_hol_block_clear_all(struct ipa *ipa)
-- 
2.32.0