Re: [linux-pm] [PATCH 1/8] ACPI / PCI: Introduce acpi_pci_osc_control_query()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thursday, August 05, 2010, Rafael J. Wysocki wrote:
> On Wednesday, August 04, 2010, Kenji Kaneshige wrote:
> > (2010/08/04 5:58), Rafael J. Wysocki wrote:
> > > On Tuesday, August 03, 2010, Rafael J. Wysocki wrote:
> > >> On Tuesday, August 03, 2010, Kenji Kaneshige wrote:
> > >>> (2010/08/03 6:53), Rafael J. Wysocki wrote:
> > >>>> From: Rafael J. Wysocki<rjw@xxxxxxx>
> > >>>
> > >>> <snip.>
> > >>>
> > >>>> +	mutex_lock(&osc_lock);
> > >>>> +	status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask);
> > >>>> +	mutex_unlock(&osc_lock);
> > >>>> +
> > >>>
> > >>> One more comment here.
> > >>>
> > >>> I think we can skip acpi_pci_query_osc() if all of queried controls are
> > >>> already granted to OS. Please see below
> > >>>
> > >>> 	mutex_lock(&osc_lock);
> > >>> 	if ((root->osc_control_set&  *ctrl_mask) == *ctrl_mask) {
> > >>> 		*ctrl_mask = root->osc_control_set;
> > >>> 		goto out;
> > >>> 	}
> > >>> 	status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask);
> > >>> 	mutex_unlock(&osc_lock);
> > >>> out:
> > >>
> > >> Well I guess you mean:
> > >>
> > >>   	mutex_lock(&osc_lock);
> > >>   	if ((root->osc_control_set&  *ctrl_mask) != *ctrl_mask)
> > >>   		status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask);
> > >>   	mutex_unlock(&osc_lock);
> > >>
> > >> Otherwise we would return with the mutex held. :-)
> > >
> > 
> > Oops... sorry...
> > 
> > > Updated patch is appended, please tell me what you think.
> > 
> > Looks good to me. The below (in your updated patch) was what I wanted to mean
> > 
> > > +	mutex_lock(&osc_lock);
> > > +	if ((*mask & root->osc_control_set) == *mask)
> > > +		*mask = root->osc_control_set;
> > > +	else
> > > +		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
> > > +	mutex_unlock(&osc_lock);
> 
> OK
> 
> However, I think we can put the looping into that function so that the caller
> doesn't have to loop.
> 
> The patch below implements that.

The patch below is incorrect, sorry.  Please disregard it.

Thanks,
Rafael


> ---
> From: Rafael J. Wysocki <rjw@xxxxxxx>
> Subject: ACPI / PCI: Introduce acpi_pci_osc_control_query() (v3)
> 
> Introduce a function allowing the caller to obtain a mask of _OSC
> control bits the BIOS will allow the kernel to control for a given
> PCI root bridge.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> ---
>  drivers/acpi/pci_root.c |   71 +++++++++++++++++++++++++++++++++++++++++-------
>  include/linux/acpi.h    |    1 
>  2 files changed, 63 insertions(+), 9 deletions(-)
> 
> Index: linux-2.6/drivers/acpi/pci_root.c
> ===================================================================
> --- linux-2.6.orig/drivers/acpi/pci_root.c
> +++ linux-2.6/drivers/acpi/pci_root.c
> @@ -225,21 +225,32 @@ static acpi_status acpi_pci_run_osc(acpi
>  	return status;
>  }
>  
> -static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
> +static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
> +					u32 support,
> +					u32 *control)
>  {
>  	acpi_status status;
> -	u32 support_set, result, capbuf[3];
> +	u32 result, capbuf[3];
> +
> +	support &= OSC_PCI_SUPPORT_MASKS;
> +	support |= root->osc_support_set;
>  
> -	/* do _OSC query for all possible controls */
> -	support_set = root->osc_support_set | (flags & OSC_PCI_SUPPORT_MASKS);
>  	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
> -	capbuf[OSC_SUPPORT_TYPE] = support_set;
> -	capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
> +	capbuf[OSC_SUPPORT_TYPE] = support;
> +	if (control) {
> +		*control &= OSC_PCI_CONTROL_MASKS;
> +		capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
> +	} else {
> +		/* Run _OSC query for all possible controls. */
> +		capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
> +	}
>  
>  	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
>  	if (ACPI_SUCCESS(status)) {
> -		root->osc_support_set = support_set;
> +		root->osc_support_set = support;
>  		root->osc_control_qry = result;
> +		if (control)
> +			*control = result;
>  		root->osc_queried = 1;
>  	}
>  	return status;
> @@ -254,7 +265,7 @@ static acpi_status acpi_pci_osc_support(
>  	if (ACPI_FAILURE(status))
>  		return status;
>  	mutex_lock(&osc_lock);
> -	status = acpi_pci_query_osc(root, flags);
> +	status = acpi_pci_query_osc(root, flags, NULL);
>  	mutex_unlock(&osc_lock);
>  	return status;
>  }
> @@ -363,6 +374,48 @@ out:
>  }
>  EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
>  
> + /**
> + * acpi_pci_osc_control_query - Get the _OSC bits the kernel can control.
> + * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
> + * @mask: Mask of _OSC bits to query and the place to put the result into.
> + **/
> +acpi_status acpi_pci_osc_control_query(acpi_handle handle, u32 *mask)
> +{
> +	struct acpi_pci_root *root;
> +	acpi_handle tmp;
> +	acpi_status status = AE_OK;
> +	u32 ctrl = *mask;
> +
> +	if (!ctrl || !(ctrl & OSC_PCI_CONTROL_MASKS))
> +		return AE_BAD_PARAMETER;
> +
> +	root = acpi_pci_find_root(handle);
> +	if (!root)
> +		return AE_NOT_EXIST;
> +
> +	status = acpi_get_handle(handle, "_OSC", &tmp);
> +	if (ACPI_FAILURE(status))
> +		return status;
> +
> +	mutex_lock(&osc_lock);
> +
> +	*mask |= root->osc_control_set;
> +	if ((ctrl & root->osc_control_set) == ctrl)
> +		goto out;
> +
> +	while (*mask && *mask != ctrl) {
> +		ctrl = *mask;
> +		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
> +		if (ACPI_FAILURE(status))
> +			break;
> +	}
> +
> + out:
> +	mutex_unlock(&osc_lock);
> +
> +	return status;
> +}
> +
>  /**
>   * acpi_pci_osc_control_set - commit requested control to Firmware
>   * @handle: acpi_handle for the target ACPI object
> @@ -396,7 +449,7 @@ acpi_status acpi_pci_osc_control_set(acp
>  
>  	/* Need to query controls first before requesting them */
>  	if (!root->osc_queried) {
> -		status = acpi_pci_query_osc(root, root->osc_support_set);
> +		status = acpi_pci_query_osc(root, root->osc_support_set, NULL);
>  		if (ACPI_FAILURE(status))
>  			goto out;
>  	}
> Index: linux-2.6/include/linux/acpi.h
> ===================================================================
> --- linux-2.6.orig/include/linux/acpi.h
> +++ linux-2.6/include/linux/acpi.h
> @@ -305,6 +305,7 @@ acpi_status acpi_run_osc(acpi_handle han
>  				OSC_PCI_EXPRESS_AER_CONTROL |		\
>  				OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL)
>  
> +extern acpi_status acpi_pci_osc_control_query(acpi_handle handle, u32 *mask);
>  extern acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags);
>  extern void acpi_early_init(void);
>  
> _______________________________________________
> linux-pm mailing list
> linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx
> https://lists.linux-foundation.org/mailman/listinfo/linux-pm
> 
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux