From 6e228d8cbb1cc6ba78022d406340e901e08d26e0 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Fri, 12 Nov 2021 16:22:09 -0600 Subject: [PATCH 1/2] net: ipa: HOLB register sometimes must be written twice 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 Signed-off-by: David S. Miller --- 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 5528d97110d5..006da4642a0b 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) From 816316cacad2b5abd5b41423cf04e4845239abd4 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Fri, 12 Nov 2021 16:22:10 -0600 Subject: [PATCH 2/2] net: ipa: disable HOLB drop when updating timer The head-of-line blocking timer should only be modified when head-of-line drop is disabled. One of the steps in recovering from a modem crash is to enable dropping of packets with timeout of 0 (immediate). We don't know how the modem configured its endpoints, so before we program the timer, we need to ensure HOL_BLOCK is disabled. Fixes: 84f9bd12d46db ("soc: qcom: ipa: IPA endpoints") Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/ipa_endpoint.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c index 006da4642a0b..ef790fd0ab56 100644 --- a/drivers/net/ipa/ipa_endpoint.c +++ b/drivers/net/ipa/ipa_endpoint.c @@ -853,6 +853,7 @@ static void ipa_endpoint_init_hol_block_timer(struct ipa_endpoint *endpoint, u32 offset; u32 val; + /* This should only be changed when HOL_BLOCK_EN is disabled */ offset = IPA_REG_ENDP_INIT_HOL_BLOCK_TIMER_N_OFFSET(endpoint_id); val = hol_block_timer_val(ipa, microseconds); iowrite32(val, ipa->reg_virt + offset); @@ -883,6 +884,7 @@ void ipa_endpoint_modem_hol_block_clear_all(struct ipa *ipa) if (endpoint->toward_ipa || endpoint->ee_id != GSI_EE_MODEM) continue; + ipa_endpoint_init_hol_block_enable(endpoint, false); ipa_endpoint_init_hol_block_timer(endpoint, 0); ipa_endpoint_init_hol_block_enable(endpoint, true); }