Re: [PATCH V6 01/21] irqchip: tegra: Do not disable COP IRQ during suspend

Dmitry Osipenko
2019-07-22T09:55:03Z

21.07.2019 22:40, Sowjanya Komatineni пишет:
> Tegra210 platforms use sc7 entry firmware to program Tegra LP0/SC7 entry
> sequence and sc7 entry firmware is run from COP/BPMP-Lite.
>
> So, COP/BPMP-Lite still need IRQ function to finish SC7 suspend sequence
> for Tegra210.
>
> This patch has fix for leaving the COP IRQ enabled for Tegra210 during
> interrupt controller suspend operation.
>
> Acked-by: Thierry Reding <treding@nvidia.com>
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
> drivers/irqchip/irq-tegra.c | 20 ++++++++++++++++++--
> 1 file changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/irqchip/irq-tegra.c b/drivers/irqchip/irq-tegra.c
> index e1f771c72fc4..851f88cef508 100644
> --- a/drivers/irqchip/irq-tegra.c
> +++ b/drivers/irqchip/irq-tegra.c
> @@ -44,6 +44,7 @@ static unsigned int num_ictlrs;
>
> struct tegra_ictlr_soc {
> unsigned int num_ictlrs;
> + bool supports_sc7;
> };
>
> static const struct tegra_ictlr_soc tegra20_ictlr_soc = {
> @@ -56,6 +57,7 @@ static const struct tegra_ictlr_soc tegra30_ictlr_soc = {
>
> static const struct tegra_ictlr_soc tegra210_ictlr_soc = {
> .num_ictlrs = 6,
> + .supports_sc7 = true,
> };
>
> static const struct of_device_id ictlr_matches[] = {
> @@ -67,6 +69,7 @@ static const struct of_device_id ictlr_matches[] = {
>
> struct tegra_ictlr_info {
> void __iomem *base[TEGRA_MAX_NUM_ICTLRS];
> + const struct tegra_ictlr_soc *soc;
> #ifdef CONFIG_PM_SLEEP
> u32 cop_ier[TEGRA_MAX_NUM_ICTLRS];
> u32 cop_iep[TEGRA_MAX_NUM_ICTLRS];
> @@ -147,8 +150,20 @@ static int tegra_ictlr_suspend(void)
> lic->cop_ier[i] = readl_relaxed(ictlr + ICTLR_COP_IER);
> lic->cop_iep[i] = readl_relaxed(ictlr + ICTLR_COP_IEP_CLASS);
>
> - /* Disable COP interrupts */
> - writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);
> + /*
> + * AVP/COP/BPMP-Lite is the Tegra boot processor.
> + *
> + * Tegra210 system suspend flow uses sc7entry firmware which
> + * is executed by COP/BPMP and it includes disabling COP IRQ,
> + * clamping CPU rail, turning off VDD_CPU, and preparing the
> + * system to go to SC7/LP0.
> + *
> + * COP/BPMP wakes up when COP IRQ is triggered and runs
> + * sc7entry-firmware. So need to keep COP interrupt enabled.
> + */
> + if (!lic->soc->supports_sc7)
> + /* Disable COP interrupts if SC7 is not supported */

All Tegra SoCs support SC7, hence the 'supports_sc7' and the comment
doesn't sound correct to me. Something like 'firmware_sc7' should suit
better here.

> + writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);

Secondly, I'm also not sure why COP interrupts need to be disabled for
pre-T210 at all, since COP is unused. This looks to me like it was
cut-n-pasted from downstream kernel without a good reason and could be
simply removed.

> /* Disable CPU interrupts */
> writel_relaxed(~0ul, ictlr + ICTLR_CPU_IER_CLR);
> @@ -339,6 +354,7 @@ static int __init tegra_ictlr_init(struct device_node *node,
> goto out_unmap;
> }
>
> + lic->soc = soc;
> tegra_ictlr_syscore_init();
>
> pr_info("%pOF: %d interrupts forwarded to %pOF\n",
>