Commit cc7cc02bada8 ("PCI: Query platform firmware for device power
state") augmented struct pci_platform_pm_ops with a ->get_state hook and
implemented it for acpi_pci_platform_pm, the only pci_platform_pm_ops
existing till v4.7.
However v4.8 introduced another pci_platform_pm_ops for Intel Mobile
Internet Devices with commit 5823d0893ec2 ("x86/platform/intel-mid: Add
Power Management Unit driver"). It is missing the ->get_state hook,
which is fatal since pci_set_platform_pm() enforces its presence. Andy
Shevchenko reports that without the present commit, such a device
"crashes without even a character printed out on serial console and
reboots (since watchdog)".
Retrofit mid_pci_platform_pm with the missing callback to fix the
breakage.
Fixes: cc7cc02bada8 ("PCI: Query platform firmware for device power state")
Cc: x...@kernel.org
Signed-off-by: Lukas Wunner <lu...@wunner.de>
Acked-and-tested-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelg...@google.com>
---
Changes v1 -> v2:
- Cast return value of intel_mid_pci_get_power_state() to
(__force pci_power_t) to avoid "sparse -D__CHECK_ENDIAN__" warning.
- Add ack by Andy Shevchenko.
Changes v2 -> v3:
- Amend commit message to explain the user-visible failure mode as
reported by Andy.
- Add ack by Bjorn Helgaas and Fixes tag.
arch/x86/include/asm/intel-mid.h | 1 +
arch/x86/platform/intel-mid/pwr.c | 19 +++++++++++++++++++
drivers/pci/pci-mid.c | 6 ++++++
3 files changed, 26 insertions(+)
diff --git a/arch/x86/include/asm/intel-mid.h b/arch/x86/include/asm/intel-mid.h
index 5b6753d..49da9f4 100644
--- a/arch/x86/include/asm/intel-mid.h
+++ b/arch/x86/include/asm/intel-mid.h
@@ -17,6 +17,7 @@
extern int intel_mid_pci_init(void);
extern int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t
state);
+extern pci_power_t intel_mid_pci_get_power_state(struct pci_dev *pdev);
extern void intel_mid_pwr_power_off(void);
diff --git a/arch/x86/platform/intel-mid/pwr.c
b/arch/x86/platform/intel-mid/pwr.c
index 5d3b45a..67375dd 100644
--- a/arch/x86/platform/intel-mid/pwr.c
+++ b/arch/x86/platform/intel-mid/pwr.c
@@ -272,6 +272,25 @@ int intel_mid_pci_set_power_state(struct pci_dev *pdev,
pci_power_t state)
}
EXPORT_SYMBOL_GPL(intel_mid_pci_set_power_state);
+pci_power_t intel_mid_pci_get_power_state(struct pci_dev *pdev)
+{
+ struct mid_pwr *pwr = midpwr;
+ int id, reg, bit;
+ u32 power;
+
+ if (!pwr || !pwr->available)
+ return PCI_UNKNOWN;
+
+ id = intel_mid_pwr_get_lss_id(pdev);
+ if (id < 0)
+ return PCI_UNKNOWN;
+
+ reg = (id * LSS_PWS_BITS) / 32;
+ bit = (id * LSS_PWS_BITS) % 32;
+ power = mid_pwr_get_state(pwr, reg);
+ return (__force pci_power_t)((power >> bit) & 3);
+}
+
void intel_mid_pwr_power_off(void)
{
struct mid_pwr *pwr = midpwr;
diff --git a/drivers/pci/pci-mid.c b/drivers/pci/pci-mid.c
index 55f453d..c7f3408 100644
--- a/drivers/pci/pci-mid.c
+++ b/drivers/pci/pci-mid.c
@@ -29,6 +29,11 @@ static int mid_pci_set_power_state(struct pci_dev *pdev,
pci_power_t state)
return intel_mid_pci_set_power_state(pdev, state);
}
+static pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
+{
+ return intel_mid_pci_get_power_state(pdev);
+}
+
static pci_power_t mid_pci_choose_state(struct pci_dev *pdev)
{
return PCI_D3hot;
@@ -52,6 +57,7 @@ static bool mid_pci_need_resume(struct pci_dev *dev)
static struct pci_platform_pm_ops mid_pci_platform_pm = {
.is_manageable = mid_pci_power_manageable,
.set_state = mid_pci_set_power_state,
+ .get_state = mid_pci_get_power_state,
.choose_state = mid_pci_choose_state,
.sleep_wake = mid_pci_sleep_wake,
.run_wake = mid_pci_run_wake,
--
2.9.3
