net: ipa: HOLB register sometimes must be written twice

Alex Elder · davem330 · commit 6e228d8cbb1c · 2021-11-15T13:25:45.000Z
Starting with IPA v4.5, the HOL_BLOCK_EN register must be written twice when enabling head-of-line blocking avoidance. Fixes: 84f9bd1 ("soc: qcom: ipa: IPA endpoints") Signed-off-by: Alex Elder <elder@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git 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)

Original file line number	Diff line number	Diff line change
`@@ -868,6 +868,9 @@ ipa_endpoint_init_hol_block_enable(struct ipa_endpoint *endpoint, bool enable)`
`868`	`868`	`val = enable ? HOL_BLOCK_EN_FMASK : 0;`
`869`	`869`	`offset = IPA_REG_ENDP_INIT_HOL_BLOCK_EN_N_OFFSET(endpoint_id);`
`870`	`870`	`iowrite32(val, endpoint->ipa->reg_virt + offset);`
	`871`	`+ /* When enabling, the register must be written twice for IPA v4.5+ */`
	`872`	`+ if (enable && endpoint->ipa->version >= IPA_VERSION_4_5)`
	`873`	`+ iowrite32(val, endpoint->ipa->reg_virt + offset);`
`871`	`874`	`}`
`872`	`875`
`873`	`876`	`void ipa_endpoint_modem_hol_block_clear_all(struct ipa *ipa)`