On Tue, Mar 07, 2023 at 04:11:04PM +0800, 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> > > --- > Changes in v2 > -send fragments to device driver by skb frag_list. > > Changes in v3 > -move frag_len and headroom_len setting to wwan_create_port. > > Changes in v4 > -change unreadable parameters to macro definition. > > Changes in v5 > -optimize comments for WWAN_NO_HEADROOM, WWAN_NO_FRAGMENT. > > Changes in v6 > -add reviewer to patch commit. Thanks for resending. Perhaps I am missing something terribly obvious, but this patch does not seem to apply against net-next (anymore?). I think it would be best to rebase and post a v7. Also, the version was missing from the patch subject (but present in v5).