Re: [PATCH 1/2] mwifiex: Use non-posted PCI register writes

[Andy Shevchenko]

On Thu, Sep 23, 2021 at 6:28 PM Jonas Dreßler <verdre@xxxxxxx> wrote:
> On 9/22/21 2:50 PM, Jonas Dreßler wrote:

...

> - Just calling mwifiex_write_reg() once and then blocking until the card
> wakes up using my delay-loop doesn't fix the issue, it's actually
> writing multiple times that fixes the issue
>
> These observations sound a lot like writes (and even reads) are actually
> being dropped, don't they?

It sounds like you're writing into a not ready (fully powered on) device.

To check this, try to put a busy loop for reading and check the value
till it gets 0.

Something like

  unsigned int count = 1000;

  do {
    if (mwifiex_read_reg(...) == 0)
      break;
  } while (--count);


-- 
With Best Regards,
Andy Shevchenko