Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> wrote:
>
> On 10/05/2024 06:04, Ping-Ke Shih wrote:
> > Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> wrote:
> >
> >> +
> >> +int rtl92du_hw_init(struct ieee80211_hw *hw)
> >> +{
> >> + struct rtl_usb_priv *usb_priv = rtl_usbpriv(hw);
> >> + struct rtl_usb *rtlusb = rtl_usbdev(usb_priv);
> >> + struct rtl_priv *rtlpriv = rtl_priv(hw);
> >> + struct rtl_ps_ctl *ppsc = rtl_psc(rtlpriv);
> >> + struct rtl_hal *rtlhal = rtl_hal(rtlpriv);
> >> + struct rtl_mac *mac = rtl_mac(rtlpriv);
> >> + struct rtl_phy *rtlphy = &rtlpriv->phy;
> >> + u8 val8, txpktbuf_bndy;
> >> + unsigned long flags;
> >> + int err, i;
> >> + u32 val32;
> >> + u16 val16;
> >> +
> >> + /* As this function can take a very long time
> >> + * and can be called with irqs disabled, reenable the irqs
> >> + * to let the other devices continue being serviced.
> >> + *
> >> + * It is safe doing so since our own interrupts will only be enabled
> >> + * in a subsequent step.
> >> + */
> >> + local_save_flags(flags);
> >> + local_irq_enable();
> >
> > I think you just copy and paste this chunk. I wonder if USB has the same behavior?
> > Driver force to enable IRQ is weird to me. Please check I this is really called
> > with irq disabled? If not, we can remove them.
> >
>
> Yes, I copied that. Removing it from rtl8192du makes no
> difference for me. I'm not sure how to check if the function
> is called with irq disabled. Is it raw_irqs_disabled() ?
> It returns 0 for me.
>
I can't find an exact description about irqs_disabled() under Documentation/.
Then I did google search and found a page [1] that says
Returns nonzero if local interrupt delivery is disabled; otherwise returns zero
I feel it is disallowed to call might sleeping API (like mutext()) when IRQ is
disabled. However, original code does. Take rtl92se_hw_init() as an example
rtl_op_start()
mutex_lock(&rtlpriv->locks.conf_mutex);
.adapter_start = rtl_pci_start()
rtlpriv->cfg->ops->hw_init(hw)
.hw_init = rtl92se_hw_init()
local_irq_enable();
mutex_unlock(&rtlpriv->locks.conf_mutex);
callers hold lps_mutex or ips_mutex
rtl_ps_set_rf_state()
.set_rf_power_state = rtl92s_phy_set_rf_power_state()
rtl_ps_enable_nic()
rtlpriv->cfg->ops->hw_init(hw)
.hw_init = rtl92se_hw_init()
local_irq_enable();
That means this drivers might no need local_irq_enable() nowadays. Currently
we can only remove it from USB adapters as first step.
> > [...]
> >
> >> + local_irq_disable();
> >> + local_irq_restore(flags);
> >> +
> >> + return err;
> >> +}
> >> +
> >
> >
[1] https://litux.nl/mirror/kerneldevelopment/0672327201/ch06lev1sec7.html
