On Thu, 24 Nov 2022 at 08:47, <haozhe.chang@xxxxxxxxxxxx> wrote: > > From: haozhe chang <haozhe.chang@xxxxxxxxxxxx> > > 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@xxxxxxxxxxxx> Reviewed-by: Loic Poulain <loic.poulain@xxxxxxxxxx>