Ganapathi Bhat <[email protected]> writes: > From: James Cao <[email protected]> > > Current driver has 6 Rx data URBs. Once any packet received > kernel calls our callback, in which the same URB will be > resubmitted after Rx indication. In URB submission function a new > skb will be allocated since the previous one is passed to upper > layer (freed later). Since the skb is from a special pool (not > regular memory), skb allocation may fail when kernel holds a lot > of Rx packets on some low resource platforms.
The special pool being GFP_ATOMIC allocations or what? > The URB will not be resubmitted in this no free skb case. If driver > fails to resubmit all 6 URBs, Rx will stop. To cover this scenario > check and resubmit Rx URBs in main thread. > > Signed-off-by: James Cao <[email protected]> > Signed-off-by: Cathy Luo <[email protected]> > Signed-off-by: Ganapathi Bhat <[email protected]> [...] > @@ -278,6 +279,16 @@ int mwifiex_main_process(struct mwifiex_adapter *adapter) > break; > } > > + /* Try to resubmit RX URB if sunmission failed earlier */ > + if (!atomic_read(&adapter->rx_pending) && > + adapter->iface_type == MWIFIEX_USB) { > + usb_card = adapter->card; > + if (atomic_read(&usb_card->rx_data_urb_pending) < > + MWIFIEX_RX_DATA_URB && > + adapter->if_ops.submit_rem_rx_urbs) > + adapter->if_ops.submit_rem_rx_urbs(adapter); > + } To me this just feels wrong. Normally the proceduce is to drop the frame if allocations fail, not try to reallocate. I need more convincing that this really is the right approach. -- Kalle Valo
