On 7/22/19 3:57 AM, Dmitry Osipenko wrote:
22.07.2019 13:13, Marc Zyngier пишет:
On 22/07/2019 10:54, Dmitry Osipenko wrote:
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 <tred...@nvidia.com>
Signed-off-by: Sowjanya Komatineni <skomatin...@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.
If what you're saying is true, then the whole patch is wrong, and the
SC7 property should come from DT.
It should be safe to assume that all of existing Tegra210 devices use
the firmware for SC7, hence I wouldn't say that the patch is entirely
wrong. To me it's not entirely correct.
Yes, all existing Tegra210 platforms uses sc7 entry firmware for SC7 and
AVP/COP IRQ need to be kept enabled as during suspend ATF triggers IRQ
to COP for SC7 entry fw execution.
+ 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.
Please verify that this is actually the case. Tegra-2 definitely needed
some level of poking, and I'm not keen on changing anything there until
you (or someone else) has verified it on actual HW (see e307cc8941fc).
Tested on Tegra20 and Tegra30, LP1 suspend-resume works perfectly fine
with all COP bits removed from the driver.
AFAIK, the reason why downstream needed that disabling is that it uses
proprietary firmware which is running on the COP and that firmware is
usually a BLOB audio/video DEC-ENC driver which doesn't cleanup
interrupts after itself. That firmware is not applicable for the
upstream kernel, hence there is no need to care about it.
Joseph, can you please shed some light here?
SC7 entry flow uses 3rd party ATF (arm-trusted FW) blob which is the one that
actually loads SC7 entry firmware and triggers IRQ to AVP/COP which causes COP
to wakeup and run SC7 entry FW.
So when SC7 support is enabled, IRQ need to be kept enabled and when SC7 FW
starts execution, it will disable COP IRQ.