Messages in this thread | | | Date | Wed, 23 Aug 2023 14:49:06 +0530 | Subject | Re: [PATCH v2] irqchip/qcom-pdc: add support for v3.2 HW | From | "Maulik Shah (mkshah)" <> |
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Hi Neil,
On 8/23/2023 2:21 PM, neil.armstrong@linaro.org wrote: > On 23/08/2023 10:25, Maulik Shah (mkshah) wrote: >> Hi, >> >> On 8/23/2023 1:16 PM, Neil Armstrong wrote: >>> Hi, >>> >>> On 23/08/2023 07:35, Maulik Shah (mkshah) wrote: >>>> Hi Neil, >>>> >>>> @@ -142,8 +163,17 @@ static int qcom_pdc_gic_set_type(struct >>>> irq_data *d, unsigned int type) >>>>> return -EINVAL; >>>>> } >>>>> - old_pdc_type = pdc_reg_read(IRQ_i_CFG, d->hwirq); >>>>> - pdc_reg_write(IRQ_i_CFG, d->hwirq, pdc_type); >>>>> + if (pdc_version < PDC_VERSION_3_2) { >>>>> + old_pdc_type = pdc_reg_read(IRQ_i_CFG, d->hwirq); >>>>> + pdc_reg_write(IRQ_i_CFG, d->hwirq, pdc_type); >>>>> + } else { >>>>> + u32 val; >>>>> + >>>>> + val = pdc_reg_read(IRQ_i_CFG, d->hwirq); >>>>> + old_pdc_type = val & IRQ_i_CFG_TYPE_MASK; >>>>> + pdc_reg_write(IRQ_i_CFG, d->hwirq, >>>>> + pdc_type | (val & IRQ_i_CFG_IRQ_ENABLE)); >>>>> + } >>>> While above is correct, i don't think we need version check in >>>> qcom_pdc_gic_set_type() as bits 0-2 are always for the type in >>>> old/new version as mentioned in v1. >>>> >>>> Adding one line after reading old_pdc_type should be good enough. >>> >>> Yes I understood, but while looking at the IRQ_i_CFG bits, I wanted >>> to keep the original >>> driver behavior intact by setting remaining bits to 0. >>> >>> Adding this single line changes that behavior and keeps bits 3-31 >>> to the default register value, which may have some consequences. >>> >>> If you consider it's an ok change, then I'll reduce it to this >>> single line. >> Yes this ok change to have single line and should not have any >> consequences. > > I also remember why, it's about the final check: > > 184 if (old_pdc_type != pdc_type) > 185 irq_chip_set_parent_state(d, > IRQCHIP_STATE_PENDING, false); > > We need to strip out remaining bits of old_pdc_type of this won't work as > expected, so I'll change it to : > > + old_pdc_type = pdc_reg_read(IRQ_i_CFG, d->hwirq); > + pdc_type |= (old_pdc_type & ~IRQ_i_CFG_TYPE_MASK); > + old_pdc_type &= IRQ_i_CFG_TYPE_MASK; > + pdc_reg_write(IRQ_i_CFG, d->hwirq, pdc_type); > > Is it ok for you ?
No.
old_pdc_type = pdc_reg_read(IRQ_i_CFG, d->hwirq);
+ pdc_type |= (old_pdc_type & ~IRQ_i_CFG_TYPE_MASK);
Adding above suggested single line is sufficient to make final check properly compare both old_pdc_type and new pdc_type, right?
But with your above change, It will end up comparing only bits 0-2 of old_pdc_type with updated pdc_type (which just got the other bits (3 to 31) of IRQ_i_CFG register by the ORing it with old_pdc_type).
Thanks, Maulik
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