net: ipa: header pad field only valid for AP->modem endpoint (f330fda3) · Commits · 戴 / test

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 <elder@linaro.org> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa_endpoint.c

+15 −4

Original line number	Diff line number	Diff line
		@@ -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 */

		/* 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) */
		/* HDR_PAYLOAD_LEN_INC_PADDING is 0 */
		val \|= HDR_PAYLOAD_LEN_INC_PADDING_FMASK;
		/* HDR_TOTAL_LEN_OR_PAD_OFFSET is 0 */
		}

		/* HDR_PAYLOAD_LEN_INC_PADDING is 0 */
		if (!endpoint->toward_ipa)
		val \|= u32_encode_bits(pad_align, HDR_PAD_TO_ALIGNMENT_FMASK);

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