Hi Larry, Am Donnerstag, den 14.11.2019, 15:25 -0600 schrieb Larry Finger: [...] > > > I don't know if this function needs to guard against something running > > > in the IRQ handler, so depending on the answer to that the solution > > > might be as simple as not disabling IRQs when taking the spinlock. > > > > > > kworker/-276 4d... 0us : _raw_spin_lock_irqsave > > > kworker/-276 4d... 0us : rtl8723_phy_rf_serial_read <-rtl8723de_phy_set_rf_reg > > > kworker/-276 4d... 1us : rtl8723_phy_query_bb_reg <-rtl8723_phy_rf_serial_read > > > kworker/-276 4d... 3us : rtl8723_phy_set_bb_reg <-rtl8723_phy_rf_serial_read > > > kworker/-276 4d... 4us : __const_udelay <-rtl8723_phy_rf_serial_read > > > kworker/-276 4d... 4us!: delay_mwaitx <-rtl8723_phy_rf_serial_read > > > kworker/-276 4d... 1004us : rtl8723_phy_set_bb_reg <-rtl8723_phy_rf_serial_read > > > [...] > > > > > > > I check TX/RX interrupt handlers, and I don't find one calls RF read function > > by now. I suspect that old code controls RF to do PS in interrupt context, so > > _irqsave version is used to ensure read RF isn't interrupted or deadlock. > > So, I change spin_lock to non-irqsave version, and do some tests on 8723BE > > that works well. > > > > What do you think about two fixes mentioned above? If they're ok, I can send > > two patches to resolve this long delays. > > Lucas, > > If the above patch fixes the problem with the 8723de, I will modify the GitHub > driver. Although 8723de will be added to rtw88, I will keep the driver in > rtlwifi_new. I'm currently running the rtlwifi_new based modules, modified with the reduced waits as suggested by PK, as well as removing the IRQ disable from the spinlocks in both rtl8723de_phy_query_rf_reg() and rtl8723de_phy_set_rf_reg(). I can confirm that with those changes rtl8723de no longer shows up my latency traces. Regards, Lucas
