Re: [1/8] mwifiex: prevent register accesses after host is sleeping

[Kalle Valo <kvalo@codeaurora.org>]

Amitkumar Karwar <akarwar@marvell.com> 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@marvell.com>
> Reviewed-by: Brian Norris <briannorris@chromium.org>
> Tested-by: Brian Norris <briannorris@chromium.org>

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/

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