| Message ID | 1428092835-16834-24-git-send-email-jeffrey.t.kirsher@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
On Fri, 2015-04-03 at 13:27 -0700, Jeff Kirsher wrote: > 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: Jeff Kirsher <jeffrey.t.kirsher@intel.com> > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> > Acked-by: Matthew Vick <matthew.vick@intel.com> > --- > drivers/net/ethernet/intel/fm10k/fm10k_mbx.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) I have applied to my queue.
-----Original Message----- From: Kirsher, Jeffrey T Sent: Friday, April 3, 2015 2:08 PM To: intel-wired-lan@lists.osuosl.org Cc: Keller, Jacob E; Singh, Krishneil K Subject: Re: [net-next 24/25] fm10k: mbx_update_max_size does not drop all oversized messages On Fri, 2015-04-03 at 13:27 -0700, Jeff Kirsher wrote: > 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: Jeff Kirsher <jeffrey.t.kirsher@intel.com> > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> > Acked-by: Matthew Vick <matthew.vick@intel.com> > --- > drivers/net/ethernet/intel/fm10k/fm10k_mbx.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) I have applied to my queue. -- git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue.git dev-queue Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c b/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c index 27f8279..1b27383 100644 --- a/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c +++ b/drivers/net/ethernet/intel/fm10k/fm10k_mbx.c @@ -327,7 +327,7 @@ 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 */ @@ -1063,8 +1063,11 @@ static void fm10k_mbx_reset_work(struct fm10k_mbx_info *mbx) * @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) {