[PATCH 5.15 114/279] net: ipa: HOLB register sometimes must be written twice

Greg Kroah-Hartman
2021-11-24T13:51:56Z

From: Alex Elder <elder@linaro.org>

[ Upstream commit 6e228d8cbb1cc6ba78022d406340e901e08d26e0 ]

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.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)
--
2.33.0