Re: [PATCH] cxl: disable the lazy approach for irqs in POWERVM environment.
From: Benjamin Herrenschmidt <hidden>
Date: 2018-03-23 02:14:57
On Thu, 2018-03-22 at 17:37 +0100, Christophe Lombard wrote:
The cxl driver cannot disable the interrupt at the device level and has to use disable_irq[_nosync] instead. To avoid the implementation of the lazy optimisation (the interrupt is marked disabled, but the hardware is left unmasked), we can disable it, for a particular irq line, by calling 'irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY)'.
Why do you need that ? What's wrong with the lazy approach ? It makes disable_irq/enable_irq faster... You shouldn't need that unless your device is generating a *LOT* of irqs while disabled.
quoted hunk ↗ jump to hunk
Signed-off-by: Christophe Lombard <redacted> --- drivers/misc/cxl/guest.c | 1 + 1 file changed, 1 insertion(+)diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c index f58b4b6c..dc476e1 100644 --- a/drivers/misc/cxl/guest.c +++ b/drivers/misc/cxl/guest.c@@ -389,6 +389,7 @@ static void disable_afu_irqs(struct cxl_context *ctx) hwirq = ctx->irqs.offset[r]; for (i = 0; i < ctx->irqs.range[r]; hwirq++, i++) { virq = irq_find_mapping(NULL, hwirq); + irq_set_status_flags(virq, IRQ_DISABLE_UNLAZY); disable_irq(virq); } }