SDIO Client Driver Fast-Path Support
Other versions of this page are also available for the following:
.gif "A hyphen indicates that the information in this topic is not relevant for this platform, or that the platform does not support the API that is listed.")
.gif "A checkmark indicates that the information in this topic is relevant for this platform, and that any API listed is also supported on this platform.")
8/28/2008
The following code samples illustrate how the client driver can determine if the bus driver supports Fast-Path, how the client driver can disable Fast-Path support in the bus driver, and how the client driver can restore Fast-Path support in the bus driver.
Note
The SDIO client driver does not need to be aware of Fast-Path support. Fast-Path operations are enabled by default if the SDIO host controller supports Fast-Path. A client driver only needs to make changes for Fast-Path support if it wants to disable Fast-Path operations.
During card initialization, the client driver can use the following code to determine if the bus driver supports Fast-Path.
SD_API_STATUS rStat;
//Check to see if Fast-Path is available
//If rStat returns SD_API_STATUS_SUCCESS, then Fast-Path is supported.
rStat = SDSetCardFeature ( pClientInfo -> hDevice, SD_IS_FAST_PATH_AVAILABLE, NULL, 0);
The client driver can use the following code to disable Fast-Path in the bus driver.
SD_API_STATUS rStat;
// Request that the bus driver use normal path for all
// synchronous operations.
// Check return status to see if disabling of Fast-Path
// succeeded.
rStat = SDSetCardFeature ( pClientInfo -> hDevice, SD_FAST_PATH_ALWAYS_ENABLE_DISABLE, NULL, FALSE);
The client driver can use the following code to restore Fast-Path support in the bus driver.
SD_API_STATUS rStat;
// Request that the bus driver use Fast-Path for all
// relevant synchronous operations.
// Check return status to see if enabling of Fast-Path
// succeeded.
rStat = SDSetCardFeature ( pClientInfo -> hDevice, SD_FAST_PATH_ALWAYS_ENABLE_DISABLE, NULL, TRUE);