On Tue, Sep 19, 2017 at 07:42:04PM +1000, James Cameron wrote:

On Thu, Sep 14, 2017 at 07:27:39PM +1000, James Cameron wrote:

quoted

On Wed, Sep 13, 2017 at 07:39:35PM -0500, Larry Finger wrote:

quoted

On 09/13/2017 04:46 PM, James Cameron wrote:

quoted

I'll give it some more testing and let you know, but it seems as
capable of keeping a connection as 4.13 plus my earlier revert.

Testing went well; removing the call to enable ASPM was as good as
changing the DBI read back to 16-bit width.

quoted

The change I sent earlier should be as good as reverting the change
to write_byte in your reversion.

Yes, that would be the hope.

But with the 16-bit DBI read, the register REG_DBI_CTRL+0 is being
read as well, in the first read in _rtl8821ae_enable_aspm_back_door,
so perhaps reading that register has an unexpected side-effect.

I've ruled that out after testing for several days different kernels
based on v4.13;

- add an rtl_read_byte of REG_DBI_CTRL+0 in rtl8821ae_hw_init just
  after the call to enable_aspm; does not solve problem,

- add an rtl_read_byte of REG_DBI_CTRL+0 at the start of
  _rtl8821ae_check_pcie_dma_hang; does not solve problem,

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?

[...]

-- 
James Cameron
http://quozl.netrek.org/