Commit 162fbc6f authored by Alex Elder's avatar Alex Elder Committed by Jakub Kicinski
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net: ipa: minor update to handling of packet with status 



Rearrange some comments and assignments made when handling a packet
that is received with status, aiming to improve understandability.

Use DIV_ROUND_CLOSEST() to get a better per-packet true size estimate.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Acked-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent aa56e3e5

drivers/net/ipa/ipa_endpoint.c

+17 −13
Original line number Diff line number Diff line
@@ -1213,12 +1213,11 @@ static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint, 
			continue;

		}



		/* Compute the amount of buffer space consumed by the

		 * packet, including the status element.  If the hardware

		 * is configured to pad packet data to an aligned boundary,

		 * account for that.  And if checksum offload is is enabled

		 * a trailer containing computed checksum information will

		 * be appended.

		/* Compute the amount of buffer space consumed by the packet,

		 * including the status element.  If the hardware is configured

		 * to pad packet data to an aligned boundary, account for that.

		 * And if checksum offload is enabled a trailer containing

		 * computed checksum information will be appended.

		 */

		align = endpoint->data->rx.pad_align ? : 1;

		len = le16_to_cpu(status->pkt_len);
@@ -1226,16 +1225,21 @@ static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint, 
		if (endpoint->data->checksum)

			len += sizeof(struct rmnet_map_dl_csum_trailer);



		/* Charge the new packet with a proportional fraction of

		 * the unused space in the original receive buffer.

		 * XXX Charge a proportion of the *whole* receive buffer?

		 */

		if (!ipa_status_drop_packet(status)) {

			u32 extra = unused * len / total_len;

			void *data2 = data + sizeof(*status);

			u32 len2 = le16_to_cpu(status->pkt_len);

			void *data2;

			u32 extra;

			u32 len2;



			/* Client receives only packet data (no status) */

			data2 = data + sizeof(*status);

			len2 = le16_to_cpu(status->pkt_len);



			/* Have the true size reflect the extra unused space in

			 * the original receive buffer.  Distribute the "cost"

			 * proportionately across all aggregated packets in the

			 * buffer.

			 */

			extra = DIV_ROUND_CLOSEST(unused * len, total_len);

			ipa_endpoint_skb_copy(endpoint, data2, len2, extra);

		}