• Tejun Heo's avatar
    libata: use ata_exec_internal() for PMP register access · b06ce3e5
    Tejun Heo authored
    PMP registers used to be accessed with dedicated accessors ->pmp_read
    and ->pmp_write.  During reset, those callbacks are called with the
    port frozen so they should be able to run without depending on
    interrupt delivery.  To achieve this, they were implemented polling.
    However, as resetting the host port makes the PMP to isolate fan-out
    ports until SError.X is cleared, resetting fan-out ports while port is
    frozen doesn't buy much additional safety.
    This patch updates libata PMP support such that PMP registers are
    accessed using regular ata_exec_internal() mechanism and kills
    ->pmp_read/write() callbacks.  The following changes are made.
    * PMP access helpers - sata_pmp_read_init_tf(), sata_pmp_read_val(),
      sata_pmp_write_init_tf() are folded into sata_pmp_read/write() which
      are now standalone PMP register access functions.
    * sata_pmp_read/write() returns err_mask instead of rc.  This is
      consistent with other functions which issue internal commands and
      allows more detailed error reporting.
    * ahci interrupt handler is modified to ignore BAD_PMP and
      spurious/illegal completion IRQs while reset is in progress.  These
      conditions are expected during reset.
    Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
    Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
ahci.c 55 KB