Stefan Sperling wrote: > The iwm(4) driver pre-allocates fw command payload buffers of 320 bytes. > > For some firmware commands, particularly those used when configuring > the PHY (iwm_send_phy_db_cmd) and running scans (iwm_mvm_scan_request), > the payload exceeds 320 bytes. I've seen somewhere between 2k and 3.5k > being used. Precisely these commands fail often while we're trying to > bring the interface up. You've probably seen "could not initiate scan". > The PHY failure case doesn't print anything unless IWM_DEBUG is set. > > If the payload doesn't fit, the driver tries to use an mbuf instead > of the pre-allocated payload buffer. This seems to be based on the > approach taken in iwn(4).
huh? Why an mbuf? Is dma_alloc not a better choice?
