4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 6a31061833a52a79c99221b6251db08cf377470e ]
We lose even config space access when we power gate the ISP via the PUNIT. That makes lspci & co. produce gibberish.
To fix that let's try to implement actual runtime pm hooks and inform the pci core that the device always goes to D3cold. That will cause the pci core to resume the device before attempting config space access.
This introduces another annoyance though. We get the following error every time we try to resume the device: intel_atomisp2_pm 0000:00:03.0: Refused to change power state, currently in D3
The reason being that the pci core tries to put the device back into D0 via the standard PCI PM mechanism before calling the driver resume hook. To fix this properly we'd need to infiltrate the platform pm hooks (could turn ugly real fast), or use pm domains (which don't seem to exist on x86), or some extra early resume hook for the driver (which doesn't exist either). So maybe we just choose to live with the error?
Cc: Hans de Goede hdegoede@redhat.com Cc: Alan Cox alan@linux.intel.com Cc: Andy Shevchenko andriy.shevchenko@linux.intel.com Cc: Darren Hart dvhart@infradead.org Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/intel_atomisp2_pm.c | 68 +++++++++++++++++------- 1 file changed, 48 insertions(+), 20 deletions(-)
diff --git a/drivers/platform/x86/intel_atomisp2_pm.c b/drivers/platform/x86/intel_atomisp2_pm.c index 9371603a0ac9..2a8c7a4cea35 100644 --- a/drivers/platform/x86/intel_atomisp2_pm.c +++ b/drivers/platform/x86/intel_atomisp2_pm.c @@ -33,46 +33,45 @@ #define ISPSSPM0_IUNIT_POWER_ON 0x0 #define ISPSSPM0_IUNIT_POWER_OFF 0x3
-static int isp_probe(struct pci_dev *dev, const struct pci_device_id *id) +static int isp_set_power(struct pci_dev *dev, bool enable) { unsigned long timeout; - u32 val; - - pci_write_config_dword(dev, PCI_INTERRUPT_CTRL, 0); - - /* - * MRFLD IUNIT DPHY is located in an always-power-on island - * MRFLD HW design need all CSI ports are disabled before - * powering down the IUNIT. - */ - pci_read_config_dword(dev, PCI_CSI_CONTROL, &val); - val |= PCI_CSI_CONTROL_PORTS_OFF_MASK; - pci_write_config_dword(dev, PCI_CSI_CONTROL, val); + u32 val = enable ? ISPSSPM0_IUNIT_POWER_ON : + ISPSSPM0_IUNIT_POWER_OFF;
- /* Write 0x3 to ISPSSPM0 bit[1:0] to power off the IUNIT */ + /* Write to ISPSSPM0 bit[1:0] to power on/off the IUNIT */ iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, - ISPSSPM0_IUNIT_POWER_OFF, ISPSSPM0_ISPSSC_MASK); + val, ISPSSPM0_ISPSSC_MASK);
/* * There should be no IUNIT access while power-down is * in progress HW sighting: 4567865 * Wait up to 50 ms for the IUNIT to shut down. + * And we do the same for power on. */ timeout = jiffies + msecs_to_jiffies(50); while (1) { - /* Wait until ISPSSPM0 bit[25:24] shows 0x3 */ - iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &val); - val = (val & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET; - if (val == ISPSSPM0_IUNIT_POWER_OFF) + u32 tmp; + + /* Wait until ISPSSPM0 bit[25:24] shows the right value */ + iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &tmp); + tmp = (tmp & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET; + if (tmp == val) break;
if (time_after(jiffies, timeout)) { - dev_err(&dev->dev, "IUNIT power-off timeout.\n"); + dev_err(&dev->dev, "IUNIT power-%s timeout.\n", + enable ? "on" : "off"); return -EBUSY; } usleep_range(1000, 2000); }
+ return 0; +} + +static int isp_probe(struct pci_dev *dev, const struct pci_device_id *id) +{ pm_runtime_allow(&dev->dev); pm_runtime_put_sync_suspend(&dev->dev);
@@ -87,11 +86,40 @@ static void isp_remove(struct pci_dev *dev)
static int isp_pci_suspend(struct device *dev) { + struct pci_dev *pdev = to_pci_dev(dev); + u32 val; + + pci_write_config_dword(pdev, PCI_INTERRUPT_CTRL, 0); + + /* + * MRFLD IUNIT DPHY is located in an always-power-on island + * MRFLD HW design need all CSI ports are disabled before + * powering down the IUNIT. + */ + pci_read_config_dword(pdev, PCI_CSI_CONTROL, &val); + val |= PCI_CSI_CONTROL_PORTS_OFF_MASK; + pci_write_config_dword(pdev, PCI_CSI_CONTROL, val); + + /* + * We lose config space access when punit power gates + * the ISP. Can't use pci_set_power_state() because + * pmcsr won't actually change when we write to it. + */ + pci_save_state(pdev); + pdev->current_state = PCI_D3cold; + isp_set_power(pdev, false); + return 0; }
static int isp_pci_resume(struct device *dev) { + struct pci_dev *pdev = to_pci_dev(dev); + + isp_set_power(pdev, true); + pdev->current_state = PCI_D0; + pci_restore_state(pdev); + return 0; }