The FLAVOR_0 version first appears in IPA v3.5, so avoid attempting to read it for versions prior to that. This register contains a concise definition of the number and direction of endpoints supported by the hardware, and without it we can't verify endpoint configuration in ipa_endpoint_config(). In this case, just indicate that any endpoint number is available for use. Originally proposed by AngeloGioacchino Del Regno. Link: https://lore.kernel.org/netdev/20210211175015.200772-3-angelogioacchino.delregno@xxxxxxxxxxxxxx Signed-off-by: Alex Elder <elder@xxxxxxxxxx> --- drivers/net/ipa/ipa_endpoint.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c index 3520852936ed1..ab02669bae4e6 100644 --- a/drivers/net/ipa/ipa_endpoint.c +++ b/drivers/net/ipa/ipa_endpoint.c @@ -1731,6 +1731,21 @@ int ipa_endpoint_config(struct ipa *ipa) u32 max; u32 val; + /* Prior to IPAv3.5, the FLAVOR_0 register was not supported. + * Furthermore, the endpoints were not grouped such that TX + * endpoint numbers started with 0 and RX endpoints had numbers + * higher than all TX endpoints, so we can't do the simple + * direction check used for newer hardware below. + * + * For hardware that doesn't support the FLAVOR_0 register, + * just set the available mask to support any endpoint, and + * assume the configuration is valid. + */ + if (ipa->version < IPA_VERSION_3_5) { + ipa->available = ~0; + return 0; + } + /* Find out about the endpoints supplied by the hardware, and ensure * the highest one doesn't exceed the number we support. */ -- 2.27.0