Drivers using legacy power management .suspen()/.resume() callbacks
have to manage PCI states and device's PM states themselves. They also
need to take care of standard configuration registers.
Switch to generic power management framework using a single
"struct dev_pm_ops" variable to take the unnecessary load from the driver.
This also avoids the need for the driver to directly call most of the PCI
helper functions and device power state control functions, as through
the generic framework PCI Core takes care of the necessary operations,
and drivers are required to do only device-specific jobs.
Signed-off-by: Vaibhav Gupta <[email protected]>
---
drivers/i2c/busses/i2c-eg20t.c | 36 +++++++---------------------------
1 file changed, 7 insertions(+), 29 deletions(-)
diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index eb41de22d461..843b31a0f752 100644
--- a/drivers/i2c/busses/i2c-eg20t.c
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -846,11 +846,10 @@ static void pch_i2c_remove(struct pci_dev *pdev)
kfree(adap_info);
}
-#ifdef CONFIG_PM
-static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused pch_i2c_suspend(struct device *dev)
{
- int ret;
int i;
+ struct pci_dev *pdev = to_pci_dev(dev);
struct adapter_info *adap_info = pci_get_drvdata(pdev);
void __iomem *p = adap_info->pch_data[0].pch_base_address;
@@ -872,31 +871,13 @@ static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
ioread32(p + PCH_I2CESRSTA));
- ret = pci_save_state(pdev);
-
- if (ret) {
- pch_pci_err(pdev, "pci_save_state\n");
- return ret;
- }
-
- pci_disable_device(pdev);
- pci_set_power_state(pdev, pci_choose_state(pdev, state));
-
return 0;
}
-static int pch_i2c_resume(struct pci_dev *pdev)
+static int __maybe_unused pch_i2c_resume(struct device *dev)
{
int i;
- struct adapter_info *adap_info = pci_get_drvdata(pdev);
-
- pci_set_power_state(pdev, PCI_D0);
- pci_restore_state(pdev);
-
- if (pci_enable_device(pdev) < 0) {
- pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
- return -EIO;
- }
+ struct adapter_info *adap_info = dev_get_drvdata(dev);
for (i = 0; i < adap_info->ch_num; i++)
pch_i2c_init(&adap_info->pch_data[i]);
@@ -905,18 +886,15 @@ static int pch_i2c_resume(struct pci_dev *pdev)
return 0;
}
-#else
-#define pch_i2c_suspend NULL
-#define pch_i2c_resume NULL
-#endif
+
+static SIMPLE_DEV_PM_OPS(pch_i2c_pm_ops, pch_i2c_suspend, pch_i2c_resume);
static struct pci_driver pch_pcidriver = {
.name = KBUILD_MODNAME,
.id_table = pch_pcidev_id,
.probe = pch_i2c_probe,
.remove = pch_i2c_remove,
- .suspend = pch_i2c_suspend,
- .resume = pch_i2c_resume
+ .driver.pm = &pch_i2c_pm_ops,
};
module_pci_driver(pch_pcidriver);
--
2.27.0
[+cc Jean for i801 question below]
On Thu, Aug 06, 2020 at 01:06:16AM +0530, Vaibhav Gupta wrote:
> Drivers using legacy power management .suspen()/.resume() callbacks
> have to manage PCI states and device's PM states themselves. They also
> need to take care of standard configuration registers.
>
> Switch to generic power management framework using a single
> "struct dev_pm_ops" variable to take the unnecessary load from the driver.
> This also avoids the need for the driver to directly call most of the PCI
> helper functions and device power state control functions, as through
> the generic framework PCI Core takes care of the necessary operations,
> and drivers are required to do only device-specific jobs.
>
> Signed-off-by: Vaibhav Gupta <[email protected]>
s/.suspen/.suspend/ above
These both look right to me.
Reviewed-by: Bjorn Helgaas <[email protected]>
Looking at neighboring drivers, it looks like some already use generic
PM but have unnecessary PCI code, e.g., amd_mp2_pci_suspend().
Probably already on your list.
Also, i801_suspend() looks suspicious because it writes SMBHSTCFG, but
I don't see anything corresponding in i801_resume().
> ---
> drivers/i2c/busses/i2c-eg20t.c | 36 +++++++---------------------------
> 1 file changed, 7 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
> index eb41de22d461..843b31a0f752 100644
> --- a/drivers/i2c/busses/i2c-eg20t.c
> +++ b/drivers/i2c/busses/i2c-eg20t.c
> @@ -846,11 +846,10 @@ static void pch_i2c_remove(struct pci_dev *pdev)
> kfree(adap_info);
> }
>
> -#ifdef CONFIG_PM
> -static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused pch_i2c_suspend(struct device *dev)
> {
> - int ret;
> int i;
> + struct pci_dev *pdev = to_pci_dev(dev);
> struct adapter_info *adap_info = pci_get_drvdata(pdev);
> void __iomem *p = adap_info->pch_data[0].pch_base_address;
>
> @@ -872,31 +871,13 @@ static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
> ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
> ioread32(p + PCH_I2CESRSTA));
>
> - ret = pci_save_state(pdev);
> -
> - if (ret) {
> - pch_pci_err(pdev, "pci_save_state\n");
> - return ret;
> - }
> -
> - pci_disable_device(pdev);
> - pci_set_power_state(pdev, pci_choose_state(pdev, state));
> -
> return 0;
> }
>
> -static int pch_i2c_resume(struct pci_dev *pdev)
> +static int __maybe_unused pch_i2c_resume(struct device *dev)
> {
> int i;
> - struct adapter_info *adap_info = pci_get_drvdata(pdev);
> -
> - pci_set_power_state(pdev, PCI_D0);
> - pci_restore_state(pdev);
> -
> - if (pci_enable_device(pdev) < 0) {
> - pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
> - return -EIO;
> - }
> + struct adapter_info *adap_info = dev_get_drvdata(dev);
>
> for (i = 0; i < adap_info->ch_num; i++)
> pch_i2c_init(&adap_info->pch_data[i]);
> @@ -905,18 +886,15 @@ static int pch_i2c_resume(struct pci_dev *pdev)
>
> return 0;
> }
> -#else
> -#define pch_i2c_suspend NULL
> -#define pch_i2c_resume NULL
> -#endif
> +
> +static SIMPLE_DEV_PM_OPS(pch_i2c_pm_ops, pch_i2c_suspend, pch_i2c_resume);
>
> static struct pci_driver pch_pcidriver = {
> .name = KBUILD_MODNAME,
> .id_table = pch_pcidev_id,
> .probe = pch_i2c_probe,
> .remove = pch_i2c_remove,
> - .suspend = pch_i2c_suspend,
> - .resume = pch_i2c_resume
> + .driver.pm = &pch_i2c_pm_ops,
> };
>
> module_pci_driver(pch_pcidriver);
> --
> 2.27.0
>
On Fri, Aug 07, 2020 at 03:23:21PM -0500, Bjorn Helgaas wrote:
> [+cc Jean for i801 question below]
>
> On Thu, Aug 06, 2020 at 01:06:16AM +0530, Vaibhav Gupta wrote:
> > Drivers using legacy power management .suspen()/.resume() callbacks
> > have to manage PCI states and device's PM states themselves. They also
> > need to take care of standard configuration registers.
> >
> > Switch to generic power management framework using a single
> > "struct dev_pm_ops" variable to take the unnecessary load from the driver.
> > This also avoids the need for the driver to directly call most of the PCI
> > helper functions and device power state control functions, as through
> > the generic framework PCI Core takes care of the necessary operations,
> > and drivers are required to do only device-specific jobs.
> >
> > Signed-off-by: Vaibhav Gupta <[email protected]>
>
> s/.suspen/.suspend/ above
>
> These both look right to me.
>
> Reviewed-by: Bjorn Helgaas <[email protected]>
>
> Looking at neighboring drivers, it looks like some already use generic
> PM but have unnecessary PCI code, e.g., amd_mp2_pci_suspend().
> Probably already on your list.
Yes :)
>
> Also, i801_suspend() looks suspicious because it writes SMBHSTCFG, but
> I don't see anything corresponding in i801_resume().
I will look into it.
Thanks
Vaibhav Gupta
>
> > ---
> > drivers/i2c/busses/i2c-eg20t.c | 36 +++++++---------------------------
> > 1 file changed, 7 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
> > index eb41de22d461..843b31a0f752 100644
> > --- a/drivers/i2c/busses/i2c-eg20t.c
> > +++ b/drivers/i2c/busses/i2c-eg20t.c
> > @@ -846,11 +846,10 @@ static void pch_i2c_remove(struct pci_dev *pdev)
> > kfree(adap_info);
> > }
> >
> > -#ifdef CONFIG_PM
> > -static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
> > +static int __maybe_unused pch_i2c_suspend(struct device *dev)
> > {
> > - int ret;
> > int i;
> > + struct pci_dev *pdev = to_pci_dev(dev);
> > struct adapter_info *adap_info = pci_get_drvdata(pdev);
> > void __iomem *p = adap_info->pch_data[0].pch_base_address;
> >
> > @@ -872,31 +871,13 @@ static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
> > ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
> > ioread32(p + PCH_I2CESRSTA));
> >
> > - ret = pci_save_state(pdev);
> > -
> > - if (ret) {
> > - pch_pci_err(pdev, "pci_save_state\n");
> > - return ret;
> > - }
> > -
> > - pci_disable_device(pdev);
> > - pci_set_power_state(pdev, pci_choose_state(pdev, state));
> > -
> > return 0;
> > }
> >
> > -static int pch_i2c_resume(struct pci_dev *pdev)
> > +static int __maybe_unused pch_i2c_resume(struct device *dev)
> > {
> > int i;
> > - struct adapter_info *adap_info = pci_get_drvdata(pdev);
> > -
> > - pci_set_power_state(pdev, PCI_D0);
> > - pci_restore_state(pdev);
> > -
> > - if (pci_enable_device(pdev) < 0) {
> > - pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
> > - return -EIO;
> > - }
> > + struct adapter_info *adap_info = dev_get_drvdata(dev);
> >
> > for (i = 0; i < adap_info->ch_num; i++)
> > pch_i2c_init(&adap_info->pch_data[i]);
> > @@ -905,18 +886,15 @@ static int pch_i2c_resume(struct pci_dev *pdev)
> >
> > return 0;
> > }
> > -#else
> > -#define pch_i2c_suspend NULL
> > -#define pch_i2c_resume NULL
> > -#endif
> > +
> > +static SIMPLE_DEV_PM_OPS(pch_i2c_pm_ops, pch_i2c_suspend, pch_i2c_resume);
> >
> > static struct pci_driver pch_pcidriver = {
> > .name = KBUILD_MODNAME,
> > .id_table = pch_pcidev_id,
> > .probe = pch_i2c_probe,
> > .remove = pch_i2c_remove,
> > - .suspend = pch_i2c_suspend,
> > - .resume = pch_i2c_resume
> > + .driver.pm = &pch_i2c_pm_ops,
> > };
> >
> > module_pci_driver(pch_pcidriver);
> > --
> > 2.27.0
> >
On Thu, Aug 06, 2020 at 01:06:16AM +0530, Vaibhav Gupta wrote:
> Drivers using legacy power management .suspen()/.resume() callbacks
> have to manage PCI states and device's PM states themselves. They also
> need to take care of standard configuration registers.
>
> Switch to generic power management framework using a single
> "struct dev_pm_ops" variable to take the unnecessary load from the driver.
> This also avoids the need for the driver to directly call most of the PCI
> helper functions and device power state control functions, as through
> the generic framework PCI Core takes care of the necessary operations,
> and drivers are required to do only device-specific jobs.
>
> Signed-off-by: Vaibhav Gupta <[email protected]>
Applied to for-next, thanks!
Hi Bjorn, Vaibhav,
On Fri, 07 Aug 2020 15:23:21 -0500, Bjorn Helgaas wrote:
> Also, i801_suspend() looks suspicious because it writes SMBHSTCFG, but
> I don't see anything corresponding in i801_resume().
You're right, it's buggy. Volker Rümelin's patch at:
https://patchwork.ozlabs.org/project/linux-i2c/patch/[email protected]/
should fix it. I was supposed to review it but did not, shame on me.
I'll do it today.
--
Jean Delvare
SUSE L3 Support
On Tue, Aug 25, 2020 at 11:53:42AM +0200, Jean Delvare wrote:
> Hi Bjorn, Vaibhav,
>
> On Fri, 07 Aug 2020 15:23:21 -0500, Bjorn Helgaas wrote:
> > Also, i801_suspend() looks suspicious because it writes SMBHSTCFG, but
> > I don't see anything corresponding in i801_resume().
>
> You're right, it's buggy. Volker R?melin's patch at:
>
> https://patchwork.ozlabs.org/project/linux-i2c/patch/[email protected]/
>
> should fix it. I was supposed to review it but did not, shame on me.
> I'll do it today.
Always nice when the fix is already there :) Thanks for following up
on this!
Bjorn