[PATCH v1] pmdomain: mediatek: Fix MT8183 hang on boot

[PATCH v1] pmdomain: mediatek: Fix MT8183 hang on boot

[Dmitry Osipenko]

Depending on firmware, part of the MFG domains may be left ON at boot
leaving only some MFG cores powered, to let the ACP to prefetch the GPU
region when the display controller is brought up. This doesn't play well
with an eventual delay in probing Panfrost when the display controller is
fully set up, as that would make genpd's sync_state() to power off the
domain while ACP tries to prefetch: this is causing an AXI stall,
effectively freezing the AP indefinitely. In order to prevent this from
happening, the sync_state() functionality must be obliterated on all of
the MFG domains: while this guarantees a power leakage if the bootloader
boots the kernel with MFG PDs partially powered on, this is the only way
to ensure stable operation of the SoC during boot on devices with such
firmware because, of course, those will never officially receive a
firmware update.

Fixes Kappa Chromebook hanging during system boot.

Fixes: 0e789b491ba0 ("pmdomain: core: Leave powered-on genpds on until sync_state")
Fixes: 13a4b7fb6260 ("pmdomain: core: Leave powered-on genpds on until late_initcall_sync")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/pmdomain/mediatek/mt8183-pm-domains.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/pmdomain/mediatek/mt8183-pm-domains.h b/drivers/pmdomain/mediatek/mt8183-pm-domains.h
index 3742782a2702..5e33b8628e85 100644
--- a/drivers/pmdomain/mediatek/mt8183-pm-domains.h
+++ b/drivers/pmdomain/mediatek/mt8183-pm-domains.h
@@ -47,7 +47,7 @@ static const struct scpsys_domain_data scpsys_domain_data_mt8183[] = {
 		.pwr_sta2nd_offs = 0x0184,
 		.sram_pdn_bits = 0,
 		.sram_pdn_ack_bits = 0,
-		.caps = MTK_SCPD_DOMAIN_SUPPLY,
+		.caps = MTK_SCPD_DOMAIN_SUPPLY | MTK_SCPD_KEEP_DEFAULT_OFF,
 	},
 	[MT8183_POWER_DOMAIN_MFG] = {
 		.name = "mfg",
@@ -57,7 +57,7 @@ static const struct scpsys_domain_data scpsys_domain_data_mt8183[] = {
 		.pwr_sta2nd_offs = 0x0184,
 		.sram_pdn_bits = GENMASK(8, 8),
 		.sram_pdn_ack_bits = GENMASK(12, 12),
-		.caps = MTK_SCPD_DOMAIN_SUPPLY,
+		.caps = MTK_SCPD_DOMAIN_SUPPLY | MTK_SCPD_KEEP_DEFAULT_OFF,
 	},
 	[MT8183_POWER_DOMAIN_MFG_CORE0] = {
 		.name = "mfg_core0",
@@ -67,6 +67,7 @@ static const struct scpsys_domain_data scpsys_domain_data_mt8183[] = {
 		.pwr_sta2nd_offs = 0x0184,
 		.sram_pdn_bits = GENMASK(8, 8),
 		.sram_pdn_ack_bits = GENMASK(12, 12),
+		.caps = MTK_SCPD_KEEP_DEFAULT_OFF,
 	},
 	[MT8183_POWER_DOMAIN_MFG_CORE1] = {
 		.name = "mfg_core1",
@@ -76,6 +77,7 @@ static const struct scpsys_domain_data scpsys_domain_data_mt8183[] = {
 		.pwr_sta2nd_offs = 0x0184,
 		.sram_pdn_bits = GENMASK(8, 8),
 		.sram_pdn_ack_bits = GENMASK(12, 12),
+		.caps = MTK_SCPD_KEEP_DEFAULT_OFF,
 	},
 	[MT8183_POWER_DOMAIN_MFG_2D] = {
 		.name = "mfg_2d",
@@ -85,6 +87,7 @@ static const struct scpsys_domain_data scpsys_domain_data_mt8183[] = {
 		.pwr_sta2nd_offs = 0x0184,
 		.sram_pdn_bits = GENMASK(8, 8),
 		.sram_pdn_ack_bits = GENMASK(12, 12),
+		.caps = MTK_SCPD_KEEP_DEFAULT_OFF,
 		.bp_cfg = {
 			BUS_PROT_WR(INFRA,
 				    MT8183_TOP_AXI_PROT_EN_1_MFG,
-- 
2.54.0

Re: [PATCH v1] pmdomain: mediatek: Fix MT8183 hang on boot

[AngeloGioacchino Del Regno]

On 7/22/26 15:27, Dmitry Osipenko wrote:
> Depending on firmware, part of the MFG domains may be left ON at boot
> leaving only some MFG cores powered, to let the ACP to prefetch the GPU
> region when the display controller is brought up. This doesn't play well
> with an eventual delay in probing Panfrost when the display controller is
> fully set up, as that would make genpd's sync_state() to power off the
> domain while ACP tries to prefetch: this is causing an AXI stall,
> effectively freezing the AP indefinitely. In order to prevent this from
> happening, the sync_state() functionality must be obliterated on all of
> the MFG domains: while this guarantees a power leakage if the bootloader
> boots the kernel with MFG PDs partially powered on, this is the only way
> to ensure stable operation of the SoC during boot on devices with such
> firmware because, of course, those will never officially receive a
> firmware update.
> 
> Fixes Kappa Chromebook hanging during system boot.
> 
> Fixes: 0e789b491ba0 ("pmdomain: core: Leave powered-on genpds on until sync_state")
> Fixes: 13a4b7fb6260 ("pmdomain: core: Leave powered-on genpds on until late_initcall_sync")
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>