• Claudiu Beznea's avatar
    ARM: at91: pm: preload base address of controllers in tlb · d8d667ee
    Claudiu Beznea authored
    In suspend/resume procedure for AT91 architecture different controllers
    (PMC, SHDWC, RAM, RAM PHY, SFRBU) are accessed to do the proper settings
    for power saving. Commit f0bbf179 ("ARM: at91: pm: add self-refresh
    support for sama7g5") introduced the access to RAMC PHY controller for
    SAMA7G5. The access to this controller is done after RAMC ports are
    closed, thus any TLB walk necessary for RAMC PHY virtual address will
    fail. In the development branch this was not encountered. However, on
    current kernel the issue is reproducible.
    
    To solve the issue the previous mechanism of pre-loading the TLB with
    the RAMC PHY virtual address has been used. However, only the addition
    of this new pre-load breaks the functionality for ARMv5 based
    devices (SAM9X60). This behavior has been encountered previously
    while debugging this code and using the same mechanism for pre-loading
    address for different controllers (e.g. pin controller, the assumption
    being that other requested translations are replaced from TLB).
    
    To solve this new issue the TLB flush + the extension of pre-loading
    the rest of controllers to TLB (e.g. PMC, RAMC) has been added. The
    rest of the controllers should have been pre-loaded previously, anyway.
    
    Fixes: f0bbf179 ("ARM: at91: pm: add self-refresh support for sama7g5")
    Depends-on: e42cbbe5 ("ARM: at91: pm: group constants and addresses loading")
    Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
    Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
    Link: https://lore.kernel.org/r/20210930154219.2214051-4-claudiu.beznea@microchip.com
    d8d667ee
pm_suspend.S 23.2 KB