4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com
[ Upstream commit dbdd0f58fd2cdde5cf945c9da67a2d52d32ba550 ]
There is a problem with PCMCIA system resume callbacks with respect to suspend-to-idle in which the ->suspend_noirq() callback may be invoked after the ->resume_noirq() one without resuming the system entirely in some cases. This doesn't work for PCMCIA because of the lack of symmetry between its system suspend and system resume "noirq" callbacks.
The system resume handling in PCMCIA is split between socket_early_resume() and socket_late_resume() which are called in different phases of system resume and both need to run for socket_suspend() (invoked by the system suspend "noirq" callback) to work. Specifically, socket_suspend() returns an error when called after socket_early_resume() without socket_late_resume(), so if the suspend-to-idle core detects a spurious wakeup event and attempts to put the system back to sleep, that is aborted by the error coming from socket_suspend().
Avoid that by using a new socket state flag, SOCKET_IN_RESUME, to indicate that socket_early_resume() has already run for the socket in which case socket_suspend() will do minimum handling and return 0.
This change has been tested on my venerable Toshiba Portege R500 (which is where the problem has been discovered in the first place), but admittedly I have no PCMCIA cards to test along with the socket itself.
Fixes: 33e4f80ee69b (ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle) Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com [linux@dominikbrodowski.net: follow same codepaths for both suspend variants; call ->suspend()] Signed-off-by: Dominik Brodowski linux@dominikbrodowski.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pcmcia/cs.c | 10 +++++++--- drivers/pcmcia/cs_internal.h | 1 + 2 files changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/pcmcia/cs.c +++ b/drivers/pcmcia/cs.c @@ -452,17 +452,20 @@ static int socket_insert(struct pcmcia_s
static int socket_suspend(struct pcmcia_socket *skt) { - if (skt->state & SOCKET_SUSPEND) + if ((skt->state & SOCKET_SUSPEND) && !(skt->state & SOCKET_IN_RESUME)) return -EBUSY;
mutex_lock(&skt->ops_mutex); - skt->suspended_state = skt->state; + /* store state on first suspend, but not after spurious wakeups */ + if (!(skt->state & SOCKET_IN_RESUME)) + skt->suspended_state = skt->state;
skt->socket = dead_socket; skt->ops->set_socket(skt, &skt->socket); if (skt->ops->suspend) skt->ops->suspend(skt); skt->state |= SOCKET_SUSPEND; + skt->state &= ~SOCKET_IN_RESUME; mutex_unlock(&skt->ops_mutex); return 0; } @@ -475,6 +478,7 @@ static int socket_early_resume(struct pc skt->ops->set_socket(skt, &skt->socket); if (skt->state & SOCKET_PRESENT) skt->resume_status = socket_setup(skt, resume_delay); + skt->state |= SOCKET_IN_RESUME; mutex_unlock(&skt->ops_mutex); return 0; } @@ -484,7 +488,7 @@ static int socket_late_resume(struct pcm int ret = 0;
mutex_lock(&skt->ops_mutex); - skt->state &= ~SOCKET_SUSPEND; + skt->state &= ~(SOCKET_SUSPEND | SOCKET_IN_RESUME); mutex_unlock(&skt->ops_mutex);
if (!(skt->state & SOCKET_PRESENT)) { --- a/drivers/pcmcia/cs_internal.h +++ b/drivers/pcmcia/cs_internal.h @@ -70,6 +70,7 @@ struct pccard_resource_ops { /* Flags in socket state */ #define SOCKET_PRESENT 0x0008 #define SOCKET_INUSE 0x0010 +#define SOCKET_IN_RESUME 0x0040 #define SOCKET_SUSPEND 0x0080 #define SOCKET_WIN_REQ(i) (0x0100<<(i)) #define SOCKET_CARDBUS 0x8000