PAGP_SET_RATE callback function (videoagp.h)
The AgpSetRate function reprograms the data transfer rate of the AGP chipset.
Syntax
PAGP_SET_RATE PagpSetRate;
BOOLEAN PagpSetRate(
[in] IN PVOID HwDeviceExtension,
[in] IN ULONG AgpRate
)
{...}
Parameters
[in] HwDeviceExtension
Pointer to the miniport driver's device extension.
[in] AgpRate
Specifies the transfer rate to be set. This value can be one of the following:
| Value | Meaning |
|---|---|
| VIDEO_AGP_RATE_1X | Single speed (66 Mhz) |
| VIDEO_AGP_RATE_2X | Two times single speed |
| VIDEO_AGP_RATE_4X | Four times single speed |
| VIDEO_AGP_RATE_8X | Eight times single speed |
Return value
AgpSetRate returns TRUE if it was successful in changing the transfer rate; otherwise, it returns FALSE.
Remarks
This function is available in Microsoft Windows XP and later.
The transfer rate set by the AgpSetRate function is persistent across changes in power state. The video miniport driver does not have to reset the AGP transfer rate when it changes from a low power state to a full power state. For information about change of power state, see HwVidSetPowerState.
The AgpSetRate function can be used to change an AGP chipset's data transfer rate to any of the rates shown in the preceding table, as long as that transfer rate has not been explicitly eliminated in the INF file that loaded the display driver. For more information, see Display INF File Sections.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Windows 2000 and later versions of the Windows operating systems. |
| Target Platform | Desktop |
| Header | videoagp.h (include Video.h) |
| IRQL | PASSIVE_LEVEL |