Re: [PATCH rtw-next v2 0/4] wifi: rtl8xxxu: keep RX requests available across transient errors

[Kim Wooseok]

Hi Ping-Ke,

Here are the test conditions and results to help with the v3 review. I
have listed the 13 tests reported previously first, followed by the v3
results.

The tests used an RTL8192EU USB adapter on a Raspberry Pi. I adapted the
RX changes to the Pi's existing Linux 6.18.46 RT kernel so they could be
tested on the device.

For the recovery tests below, I checked that all 32 URBs were retained,
reception resumed without restarting the interface, and stop freed the
URBs. The RX completion counts are from after the injected errors ended.

1. clean-fixed-regression
   No faults: receive for 3 seconds, down/up, then receive for another 3
   seconds. PASS: 581 and 246 packets received, with no RX errors.

2. fixed-submit11-errno63-finite
   ENOSR completion errors x32 and EAGAIN submission failures x96. PASS:
   all faults were injected; RX then made 4,699 successful completions.

3. fixed-submit11-errno71-window
   EPROTO for 2 seconds (maximum 1,024), with up to 256 EAGAIN
   submission failures. PASS: 126 completion and 256 submission faults
   were injected; RX then made 5,227 successful completions.

4. fixed-submit11-errno75-finite
   EOVERFLOW completion errors x32 and EAGAIN submission failures x96.
   PASS: all faults were injected; RX then made 3,420 successful
   completions.

5. fixed-submit11-errno84-finite
   EILSEQ completion errors x32 and EAGAIN submission failures x96.
   PASS: all faults were injected; RX then made 4,243 successful
   completions.

6. fixed-submit12-errno62-finite
   ETIME completion errors x32 and ENOMEM submission failures x96. PASS:
   all faults were injected; RX then made 5,340 successful completions.

7. fixed-submit12-errno70-finite
   ECOMM completion errors x32 and ENOMEM submission failures x96. PASS:
   all faults were injected; RX then made 2,848 successful completions.

8. fixed-submit12-errno71-finite
   EPROTO completion errors x32 and ENOMEM submission failures x96.
   PASS: all faults were injected; RX then made 5,321 successful
   completions.

9. fixed-submit12-errno71-finite-control24
   EPROTO completion errors x24, with no submission faults. PASS: RX
   then made 4,921 successful completions.

10. fixed-submit12-errno71-finite-stop
   EPROTO budget 32 and ENOMEM budget 256; stop as soon as a retry is
   pending. PASS: stop saw two retry URBs after two completion faults
   and no submission faults; all RX URBs were released.

11. start-alloc8
   Fail the eighth RX URB allocation with ENOMEM. PASS: start returned
   failure and released its resources; the next start restored the pool
   and reception.

12. start-fatal8
   Fail the eighth RX submission with ENODEV. PASS: start returned
   failure and released its resources; the next start restored the pool
   and reception.

13. start-temporary
   Fail 64 RX submissions with ENOMEM beginning at startup. PASS: start
   succeeded, two delayed retry runs restored the pool and reception,
   and stop released the URBs.

V3 passed 52 tests: 42 from the main test plan, one matched-input
comparison, and nine first-start failure tests after a fresh module
load. Two interrupt-URB tests were not run because the RTL8192EU does
not use that path.

With the same 32-URB pool and 24 injected EPROTO completion errors, the
unpatched driver stalled with eight pending URBs and none in flight. V3
retained all 32 URBs and received 1,225 packets over 30 seconds without
restarting the interface.

Each of the nine first-start tests began before the driver had ever
started after probe. The first start failed and cleaned up; the next
start received packets normally.

Thanks,
Kim Wooseok