[dpdk-dev] [PATCH 07/16] fm10k: mbx_update_max_size does not drop all
Wang Xiao W
xiao.w.wang at intel.com
Mon Jul 27 10:42:30 CEST 2015
When we call update_max_size, it does not drop all oversized messages.
This is due to the difficulty in performing this operation, since it is
a FIFO which makes updating anything other than head or tail very
difficult. To fix this, modify validate_msg_size to ensure that we error
out later when trying to transmit the message that could be oversized.
This will generally be a rare condition, as it requires the FIFO to
include a message larger than the max_size negotiated during mailbox
connect. Note that max_size is always smaller than rx.size, so it should
be safe to use here.
Also, update the update_max_size function header comment to clearly
indicate that it does not drop all oversized messages, but only those at
the head of the FIFO.
Signed-off-by: Wang Xiao W <xiao.w.wang at intel.com>
---
drivers/net/fm10k/base/fm10k_mbx.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/net/fm10k/base/fm10k_mbx.c b/drivers/net/fm10k/base/fm10k_mbx.c
index 12f10f8..0cdd24d 100644
--- a/drivers/net/fm10k/base/fm10k_mbx.c
+++ b/drivers/net/fm10k/base/fm10k_mbx.c
@@ -344,7 +344,7 @@ STATIC u16 fm10k_mbx_validate_msg_size(struct fm10k_mbx_info *mbx, u16 len)
} while (total_len < len);
/* message extends out of pushed section, but fits in FIFO */
- if ((len < total_len) && (msg_len <= mbx->rx.size))
+ if ((len < total_len) && (msg_len <= mbx->max_size))
return 0;
/* return length of invalid section */
@@ -1088,12 +1088,15 @@ STATIC void fm10k_mbx_reset_work(struct fm10k_mbx_info *mbx)
}
/**
- * fm10k_mbx_update_max_size - Update the max_size and drop any large messages
+ * fm10k_mbx_update_max_size - Update the max_size and drop large messages
* @mbx: pointer to mailbox
* @size: new value for max_size
*
- * This function will update the max_size value and drop any outgoing messages
- * from the head of the Tx FIFO that are larger than max_size.
+ * This function updates the max_size value and drops any outgoing messages
+ * at the head of the Tx FIFO if they are larger than max_size. It does not
+ * drop all messages, as this is too difficult to parse and remove them from
+ * the FIFO. Instead, rely on the checking to ensure that messages larger
+ * than max_size aren't pushed into the memory buffer.
**/
STATIC void fm10k_mbx_update_max_size(struct fm10k_mbx_info *mbx, u16 size)
{
--
1.9.3
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