On 09/20/2017 04:36 AM, James Cameron wrote:

When the problem occurs, register 0x350 bit 25 is set, for which a
comment in _rtl8821ae_check_pcie_dma_hang says means there is an RX
hang.

So perhaps driver should call _rtl8821ae_check_pcie_dma_hang
and _rtl8821ae_reset_pcie_interface_dma.

Any ideas where to do this?

Thanks for the extended debugging.

I was able to repeat your findings. With the 8-bit read of REG_DBI_RDATA, I got 
poor connection stability. Reverting that part made it stable again. For that 
reason, I pushed the partial reversion of commit 40b368af4b75 ("rtlwifi: Fix 
alignment issues").

Where did you detect that bit 25 of register 0x350 was set?

Larry