wwan_port_fops_write inputs the SKB parameter to the TX callback of
the WWAN device driver. However, the WWAN device (e.g., t7xx) may
have an MTU less than the size of SKB, causing the TX buffer to be
sliced and copied once more in the WWAN device driver.
This patch implements the slicing in the WWAN subsystem and gives
the WWAN devices driver the option to slice(by frag_len) or not. By
doing so, the additional memory copy is reduced.
Meanwhile, this patch gives WWAN devices driver the option to reserve
headroom in fragments for the device-specific metadata.
Signed-off-by: haozhe chang <haozhe.chang@mediatek.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/20230316095826.181904-1-haozhe.chang@mediatek.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch brings in support for device trace collection.
It implements relayfs interface for pushing device trace
from kernel space to user space.
Driver gets the debugfs base directory associated to WWAN
Device and creates trace_control and trace debugfs for
device tracing. Both trace_control & trace debugfs are
created under /sys/kernel/debug/wwan/wwan0/.
In order to collect device trace on trace0 interface, user
need to write 1 to trace_ctl interface.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implements wwan port for MBIM & AT protocol communication
Signed-off-by: M Chetan Kumar <m.chetan.kumar@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
