[rt2x00-users] [RFC 2/9] rt2x00: convert to threaded interrupts

[Ivo Van Doorn]

On Mon, Jul 5, 2010 at 6:20 PM, Helmut Schaa
<helmut.schaa at googlemail.com> wrote:
> Convert all rt2x00 pci drivers to threaded interrupts. This has several
> generic advantages:
> - The time we spend in hard irq context is reduced
> - We can use non atomic mac80211 functions for rx/tx
>
> This patch is also needed for implementing proper broad- and multicast
> buffering in AP mode and proper beacon updating during the pre tbtt
> interrupt.
>
> Signed-off-by: Helmut Schaa <helmut.schaa at googlemail.com>
> ---
>  drivers/net/wireless/rt2x00/rt2400pci.c |   52 ++++++++++++++++-------
>  drivers/net/wireless/rt2x00/rt2500pci.c |   52 ++++++++++++++++-------
>  drivers/net/wireless/rt2x00/rt2800pci.c |   46 +++++++++++++++-----
>  drivers/net/wireless/rt2x00/rt2x00.h    |   11 +++++
>  drivers/net/wireless/rt2x00/rt2x00dev.c |    6 +-
>  drivers/net/wireless/rt2x00/rt2x00pci.c |    6 ++-
>  drivers/net/wireless/rt2x00/rt61pci.c   |   71 ++++++++++++++++++++++--------
>  7 files changed, 178 insertions(+), 66 deletions(-)
>
> diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
> index b627fdc..fcb1cce 100644
> --- a/drivers/net/wireless/rt2x00/rt2400pci.c
> +++ b/drivers/net/wireless/rt2x00/rt2400pci.c
> @@ -1231,23 +1231,10 @@ static void rt2400pci_txdone(struct rt2x00_dev *rt2x00dev,
>        }
>  }
>
> -static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
> +static irqreturn_t rt2400pci_interrupt_thread(int irq, void *dev_instance)
>  {
>        struct rt2x00_dev *rt2x00dev = dev_instance;
> -       u32 reg;
> -
> -       /*
> -        * Get the interrupt sources & saved to local variable.
> -        * Write register value back to clear pending interrupts.
> -        */
> -       rt2x00pci_register_read(rt2x00dev, CSR7, &reg);
> -       rt2x00pci_register_write(rt2x00dev, CSR7, reg);
> -
> -       if (!reg)
> -               return IRQ_NONE;
> -
> -       if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
> -               return IRQ_HANDLED;
> +       u32 reg = rt2x00dev->irqvalue[0];
>
>        /*
>         * Handle interrupts, walk through all bits
> @@ -1285,9 +1272,43 @@ static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
>        if (rt2x00_get_field32(reg, CSR7_TXDONE_TXRING))
>                rt2400pci_txdone(rt2x00dev, QID_AC_BK);
>
> +       /* Enable interrupts again. */
> +       rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
> +       reg &= ~rt2x00dev->irqmask[0];
> +       rt2x00pci_register_write(rt2x00dev, CSR8, reg);
> +

Cant this be replaced with:
rt2400pci_toggle_irq(rt2x00dev, STATE_RADIO_IRQ_ON)
That way we keep the IRQ changing code in one location,
and we keep the code clearer compared to using masks which
obscure the real action.

>        return IRQ_HANDLED;
>  }
>
> +static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
> +{
> +       struct rt2x00_dev *rt2x00dev = dev_instance;
> +       u32 reg;
> +
> +       /*
> +        * Get the interrupt sources & saved to local variable.
> +        * Write register value back to clear pending interrupts.
> +        */
> +       rt2x00pci_register_read(rt2x00dev, CSR7, &reg);
> +       rt2x00pci_register_write(rt2x00dev, CSR7, reg);
> +
> +       if (!reg)
> +               return IRQ_NONE;
> +
> +       if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
> +               return IRQ_HANDLED;
> +
> +       /* Store irqvalues for use in the interrupt thread. */
> +       rt2x00dev->irqvalue[0] = reg;
> +
> +       /* Disable interrupts, will be enabled again in the interrupt thread. */
> +       rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
> +       reg |= rt2x00dev->irqmask[0];
> +       rt2x00pci_register_write(rt2x00dev, CSR8, reg);

Cant this be replaced with:
rt2400pci_toggle_irq(rt2x00dev, STATE_RADIO_IRQ_OFF)

> +       return IRQ_WAKE_THREAD;
> +}
> +
>  /*
>  * Device probe functions.
>  */
> @@ -1587,6 +1608,7 @@ static const struct ieee80211_ops rt2400pci_mac80211_ops = {
>
>  static const struct rt2x00lib_ops rt2400pci_rt2x00_ops = {
>        .irq_handler            = rt2400pci_interrupt,
> +       .irq_handler_thread     = rt2400pci_interrupt_thread,
>        .probe_hw               = rt2400pci_probe_hw,
>        .initialize             = rt2x00pci_initialize,
>        .uninitialize           = rt2x00pci_uninitialize,

Ivo