[PATCH 3/5] nvme: Add nvme_core.force_apst to ignore the NO_APST quirk

From: Andy Lutomirski
Date: Wed Apr 19 2017 - 23:02:40 EST


We're probably going to be stuck quirking APST off on an over-broad
range of devices for 4.11. Let's make it easy to override the quirk
for testing.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
drivers/nvme/host/core.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 52b4e52b85a2..b422996f88ed 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -62,6 +62,10 @@ module_param(default_ps_max_latency_us, ulong, 0644);
MODULE_PARM_DESC(default_ps_max_latency_us,
"max power saving latency for new devices; use PM QOS to change per device");

+static bool force_apst;
+module_param(force_apst, bool, 0644);
+MODULE_PARM_DESC(force_apst, "allow APST for newly enumerated devices even if quirked off");
+
static LIST_HEAD(nvme_ctrl_list);
static DEFINE_SPINLOCK(dev_list_lock);

@@ -1519,7 +1523,16 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)

ctrl->npss = id->npss;
prev_apsta = ctrl->apsta;
- ctrl->apsta = (ctrl->quirks & NVME_QUIRK_NO_APST) ? 0 : id->apsta;
+ if (ctrl->quirks & NVME_QUIRK_NO_APST) {
+ if (force_apst && id->apsta) {
+ dev_warn(ctrl->dev, "forcibly allowing APST due to nvme_core.force_apst -- use at your own risk\n");
+ ctrl->apsta = 1;
+ } else {
+ ctrl->apsta = 0;
+ }
+ } else {
+ ctrl->apsta = id->apsta;
+ }
memcpy(ctrl->psd, id->psd, sizeof(ctrl->psd));

if (ctrl->ops->is_fabrics) {
--
2.9.3