From f330fda331d276464baec8ba938d031b4adcf5c7 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 11 Jun 2020 14:48:33 -0500 Subject: net: ipa: header pad field only valid for AP->modem endpoint Only QMAP endpoints should be configured to find a pad size field within packet headers. They are found in the first byte of the QMAP header (and the hardware fills only the 6 bits in that byte that constitute the pad_len field). The RMNet driver assumes the pad_len field is valid for received packets, so we want to ensure the pad_len field is filled in that case. That driver also assumes the length in the QMAP header includes the pad bytes. The RMNet driver does *not* pad the packets it sends, so the pad_len field can be ignored. Fix ipa_endpoint_init_hdr_ext() so it only marks the pad field offset valid for QMAP RX endpoints, and in that case indicates that the length field in the header includes the pad bytes. Signed-off-by: Alex Elder Signed-off-by: David S. Miller --- drivers/net/ipa/ipa_endpoint.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c index bf3e8ced3ee0..9f50d0d11704 100644 --- a/drivers/net/ipa/ipa_endpoint.c +++ b/drivers/net/ipa/ipa_endpoint.c @@ -467,7 +467,7 @@ static void ipa_endpoint_init_hdr(struct ipa_endpoint *endpoint) header_size += sizeof(struct rmnet_map_ul_csum_header); val |= u32_encode_bits(header_size, HDR_LEN_FMASK); - /* Define how to fill mux_id in a received QMAP header */ + /* Define how to fill fields in a received QMAP header */ if (!endpoint->toward_ipa) { u32 off; /* Field offset within header */ @@ -499,10 +499,21 @@ static void ipa_endpoint_init_hdr_ext(struct ipa_endpoint *endpoint) u32 val = 0; val |= HDR_ENDIANNESS_FMASK; /* big endian */ - val |= HDR_TOTAL_LEN_OR_PAD_VALID_FMASK; - /* HDR_TOTAL_LEN_OR_PAD is 0 (pad, not total_len) */ + + /* A QMAP header contains a 6 bit pad field at offset 0. The RMNet + * driver assumes this field is meaningful in packets it receives, + * and assumes the header's payload length includes that padding. + * The RMNet driver does *not* pad packets it sends, however, so + * the pad field (although 0) should be ignored. + */ + if (endpoint->data->qmap && !endpoint->toward_ipa) { + val |= HDR_TOTAL_LEN_OR_PAD_VALID_FMASK; + /* HDR_TOTAL_LEN_OR_PAD is 0 (pad, not total_len) */ + val |= HDR_PAYLOAD_LEN_INC_PADDING_FMASK; + /* HDR_TOTAL_LEN_OR_PAD_OFFSET is 0 */ + } + /* HDR_PAYLOAD_LEN_INC_PADDING is 0 */ - /* HDR_TOTAL_LEN_OR_PAD_OFFSET is 0 */ if (!endpoint->toward_ipa) val |= u32_encode_bits(pad_align, HDR_PAD_TO_ALIGNMENT_FMASK); -- cgit v1.2.3