[Intel-gfx] [PATCH 4/6] drm/i915/glk: Don't enable DDI IO power domains during init

[Ander Conselvan de Oliveira]

In Geminilake, the DDI IO power domains can't be enabled before a DPLL
is running and mapped to the appropriate DDI. At least on Geminilake,
attempting to enable those during init will lead to a timeout.

The failure to enable the power domain also causes issues with the state
verifier during resume from suspend. After all the init power domains
are enabled, the call to intel_power_domains_sync_hw() from the resume
path will cause the hw_enabled field on the respective power wells to be
false while the usage count remains above zero. Further attempts to
enable the power domain caused by a modeset will simply update the usage
count without doing anything else. When the state verifier attempts to
read the state of a DDI encoder, intel_display_power_get_if_enabled()
returns false, leading to the following WARN:

WARNING: CPU: 3 PID: 1743 at drivers/gpu/drm/i915/intel_display.c:7001 verify_connector_state.isra.80+0x26c/0x2b0 [i915]
attached crtc is active, but connector isn't
Modules linked in: i915(E) tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_broute bridge stp llc ebtable_nat ip6table_mangle ip6table_security ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_raw iptable_mangle iptable_security iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables x86_pkg_temp_thermal coretemp kvm_intel kvm i2c_algo_bit drm_kms_helper irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel drm shpchp tpm_tis tpm_tis_core tpm nfsd auth_rpcgss nfs_acl lockd grace sunrpc crc32c_intel serio_raw [last unloaded: i915]
CPU: 3 PID: 1743 Comm: kworker/u8:22 Tainted: G        W   E   4.10.0-rc3ander+ #300
Hardware name: Intel Corp. Geminilake/GLK RVP1 DDR4 (05), BIOS GELKRVPA.X64.0023.B40.1611302145 11/30/2016
Workqueue: events_unbound async_run_entry_fn
Call Trace:
 dump_stack+0x86/0xc3
 __warn+0xcb/0xf0
 warn_slowpath_fmt+0x5f/0x80
 verify_connector_state.isra.80+0x26c/0x2b0 [i915]
 intel_atomic_commit_tail+0x520/0x1000 [i915]
 ? remove_wait_queue+0x70/0x70
 intel_atomic_commit+0x3f8/0x520 [i915]
 ? intel_runtime_pm_put+0x6e/0xa0 [i915]
 drm_atomic_commit+0x4b/0x50 [drm]
 __intel_display_resume+0x72/0xc0 [i915]
 intel_display_resume+0x107/0x150 [i915]
 i915_drm_resume+0xe0/0x180 [i915]
 i915_pm_restore+0x1e/0x30 [i915]
 i915_pm_resume+0xe/0x10 [i915]
 pci_pm_resume+0x64/0xa0
 dpm_run_callback+0xa1/0x2a0
 ? pci_pm_thaw+0x90/0x90
 device_resume+0xe3/0x200
 async_resume+0x1d/0x50
 async_run_entry_fn+0x39/0x170
 process_one_work+0x212/0x670
 ? process_one_work+0x197/0x670
 worker_thread+0x4e/0x490
 kthread+0x101/0x140
 ? process_one_work+0x670/0x670
 ? kthread_create_on_node+0x60/0x60
 ret_from_fork+0x2a/0x40

Cc: David Weinehall <david.weinehall at linux.intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>
---
 drivers/gpu/drm/i915/intel_runtime_pm.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 8795679..b729a39 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -469,14 +469,11 @@ static void hsw_set_power_well(struct drm_i915_private *dev_priv,
 	BIT_ULL(POWER_DOMAIN_VGA) |				\
 	BIT_ULL(POWER_DOMAIN_INIT))
 #define GLK_DISPLAY_DDI_A_POWER_DOMAINS (		\
-	BIT_ULL(POWER_DOMAIN_PORT_DDI_A_LANES) |		\
-	BIT_ULL(POWER_DOMAIN_INIT))
+	BIT_ULL(POWER_DOMAIN_PORT_DDI_A_LANES))
 #define GLK_DISPLAY_DDI_B_POWER_DOMAINS (		\
-	BIT_ULL(POWER_DOMAIN_PORT_DDI_B_LANES) |		\
-	BIT_ULL(POWER_DOMAIN_INIT))
+	BIT_ULL(POWER_DOMAIN_PORT_DDI_B_LANES))
 #define GLK_DISPLAY_DDI_C_POWER_DOMAINS (		\
-	BIT_ULL(POWER_DOMAIN_PORT_DDI_C_LANES) |		\
-	BIT_ULL(POWER_DOMAIN_INIT))
+	BIT_ULL(POWER_DOMAIN_PORT_DDI_C_LANES))
 #define GLK_DPIO_CMN_A_POWER_DOMAINS (			\
 	BIT_ULL(POWER_DOMAIN_PORT_DDI_A_LANES) |		\
 	BIT_ULL(POWER_DOMAIN_AUX_A) |			\
-- 
2.9.3