Re: rtl8821ae keep alive not set, connection lost

[James Cameron <quozl@laptop.org>]

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:
> > On Wed, Sep 13, 2017 at 07:39:35PM -0500, Larry Finger wrote:
> > > On 09/13/2017 04:46 PM, James Cameron wrote:
> > > >
> > > >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.
> > 
> > > 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/