Hi, This is a serials Medfield mmc driver patches to implement the eMMC mutex (Dekker Algorithm) support on IA side.
One of the Medfield eMMC controller (PCI device id 0x0823, SDIO3) is a shared resource used by the SCU and the IA processors. SCU primarily uses the eMMC host controller to access the eMMC device's Boot Partition, while the IA CPU uses the eMMC host controller to access the eMMC device's User Partition. After the SCU hands off the system to the IA processor, the IA processor assumes ownership to the eMMC host controller. Due to absence of any arbitration at the eMMC host controller, this could result in concurrent eMMC host accesses resulting in bus contention and garbage data ending up in either of the partitions. To circumvent this from happening, eMMC host controller locking mechanism is employed, where at any one given time, only one agent, SCU or IA, may be allowed to access the host. This is achieved by implementing Dekker's Algorithm (http://en.wikipedia.org/wiki/Dekker's_algorithm) between the two processors. Here is the patch list: [patch v2 1/2]MFLD mmc: Implement the eMMC mutex acquire/release APIs [patch v2 2/2]MFLD mmc: Use the mutex to protect eMMC0 host controller Thanks. Yunpeng _______________________________________________ MeeGo-kernel mailing list [email protected] http://lists.meego.com/listinfo/meego-kernel
