NAME

mac_tx_update, mac_tx_ring_update — indicate that a device can transmit again

SYNOPSIS

#include <sys/mac_provider.h>

void
mac_tx_update(mac_handle_t mh);

void
mac_tx_ring_update(mac_handle_t mh, mac_ring_handle_t mrh);

INTERFACE LEVEL

illumos DDI specific

The mac_tx_ring_update() function point is Uncommitted - API and ABI stability is not guaranteed.

PARAMETERS

mh: The MAC handle obtained from a call to mac_register(9F).
mrh: The MAC ring handle obtained when the driver's ring entry point mr_rget(9E) was called.

DESCRIPTION

The mac_tx_update() function is used by device drivers to indicate that the device represented by the handle mh can transmit data again. It should only be called after the device driver has returned data from its mc_tx(9E) endpoint. For more information on when this should be called, see both mc_tx(9E) and the Transmitting Data and Back Pressure section of mac(9E).

Device drivers should not hold any of their own locks when calling into this function. See the MAC Callbacks section of mac(9E) for more information.

When a driver has negotiated the MAC_CAPAB_RINGS capability and indicated that it supports transmit groups, it must not use the mac_tx_update() function and should instead call the mac_tx_ring_update() function targeting a specific ring instead. The ring that is being updated is specified by the ring handle passed in the mrh argument. The ring should have previously returned frames from its mri_tx(9E) entry point to indicate that it was blocked.

In all other respects, the mac_tx_ring_update() function is similar to the mac_tx_update() function.

CONTEXT

The mac_tx_update() function may be called from user, kernel, or interrupt context.