Eric Lee / smarc-fsl-linux-kernel

08 Nov, 2011

1 commit

  • b923d40dd   ARM: OMAP2PLUS: DSS: Ensure DSS works correctly if display is enabled in bootloader ... Browse Code ยป

    Resetting DISPC when a DISPC output is enabled causes the DSS to go into an
    inconsistent state. Thus if the bootloader has enabled a display, the hwmod code
    cannot reset the DISPC module just like that, but the outputs need to be
    disabled first.

    Add function dispc_disable_outputs() which disables all active overlay manager
    and ensure all frame transfers are completed.

    Modify omap_dss_reset() to call this function and clear DSS_CONTROL,
    DSS_SDI_CONTROL and DSS_PLL_CONTROL so that DSS is in a clean state when the
    DSS2 driver starts.

    This resolves the hang issue(caused by a L3 error during boot) seen on the
    beagle board C3, which has a factory bootloader that enables display. The issue
    is resolved with this patch.

    Thanks to Tomi and Sricharan for some additional testing.

    Acked-by: Tomi Valkeinen
    Tested-by: R, Sricharan
    Signed-off-by: Archit Taneja
    [paul@pwsan.com: restructured code, removed omap_{read,write}l(), removed
    cpu_is_omap*() calls and converted to dev_attr]
    Signed-off-by: Paul Walmsley

    Archit Taneja