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13 July 2024, 08:20:57 UTC
Revision 3e26c5feed2add218046ecf91bab3cfa9bf762a6 authored by Rafael J. Wysocki on 13 June 2019, 21:59:45 UTC, committed by Rafael J. Wysocki on 13 June 2019, 22:03:27 UTC 
PCI: PM: Skip devices in D0 for suspend-to-idle
 
Commit d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue")
attempted to avoid a problem with devices whose drivers want them to
stay in D0 over suspend-to-idle and resume, but it did not go as far
as it should with that.

Namely, first of all, the power state of a PCI bridge with a
downstream device in D0 must be D0 (based on the PCI PM spec r1.2,
sec 6, table 6-1, if the bridge is not in D0, there can be no PCI
transactions on its secondary bus), but that is not actively enforced
during system-wide PM transitions, so use the skip_bus_pm flag
introduced by commit d491f2b75237 for that.

Second, the configuration of devices left in D0 (whatever the reason)
during suspend-to-idle need not be changed and attempting to put them
into D0 again by force is pointless, so explicitly avoid doing that.

Fixes: d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue")
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
1 parent d1fdb6d
History
Tip revision: 3e26c5feed2add218046ecf91bab3cfa9bf762a6 authored by Rafael J. Wysocki on 13 June 2019, 21:59:45 UTC
PCI: PM: Skip devices in D0 for suspend-to-idle
Tip revision: 3e26c5f
File Mode Size
fdp
microread
nfcmrvl
nxp-nci
pn533
pn544
s3fwrn5
st-nci
st21nfca
st95hf
Kconfig -rw-r--r-- 1.8 KB
Makefile -rw-r--r-- 590 bytes
mei_phy.c -rw-r--r-- 8.4 KB
mei_phy.h -rw-r--r-- 1.2 KB
nfcsim.c -rw-r--r-- 9.9 KB
port100.c -rw-r--r-- 42.2 KB
trf7970a.c -rw-r--r-- 62.0 KB
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