Amitkumar Karwar <akarwar@xxxxxxxxxxx> wrote: > Following is mwifiex driver-firmware host sleep handshake. > It involves three threads. suspend handler, interrupt handler, interrupt > processing in main work queue. > > 1) Enter suspend handler > 2) Download HS_CFG command > 3) Response from firmware for HS_CFG > 4) Suspend thread waits until handshake completes(i.e hs_activate becomes > true) > 5) SLEEP from firmware > 6) SLEEP confirm downloaded to firmware. > 7) SLEEP confirm response from firmware > 8) Driver processes SLEEP confirm response and set hs_activate to wake up > suspend thread > 9) Exit suspend handler > 10) Read sleep cookie in loop and wait until it indicates firmware is > sleep. > 11) After processing SLEEP confirm response, we are at the end of interrupt > processing routine. Recheck if there are interrupts received while we were > processing them. > > During suspend-resume stress test, it's been observed that we may end up > acessing PCIe hardware(in 10 and 11) when PCIe bus is closed which leads > to a kernel crash. > > This patch solves the problem with below changes. > a) action 10 above can be done before 8 > b) Skip 11 if hs_activated is true. SLEEP confirm response > is the last interrupt from firmware. No need to recheck for > pending interrupts. > c) Add flush_workqueue() in suspend handler. > > Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx> > Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx> > Tested-by: Brian Norris <briannorris@xxxxxxxxxxxx> 8 patches applied to wireless-drivers-next.git, thanks. ec815dd2a5f1 mwifiex: prevent register accesses after host is sleeping 5190f2e40591 mwifiex: report error to PCIe for suspend failure c44c040300d7 mwifiex: Fix NULL pointer dereference in skb_dequeue() 113630b581d6 mwifiex: vendor_ie length check for parse WMM IEs a936ea543657 mwifiex: add memrw command information in README 77f486c8bb39 mwifiex: update tx_pkts_queued for requeued packets 49abe5c83cd0 mwifiex: fix command timeout problem seen in stress tests 3d8bd85c2c9e mwifiex: fix p2p device doesn't find in scan problem -- https://patchwork.kernel.org/patch/9353809/ Documentation about submitting wireless patches and checking status from patchwork: https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
