• Ben Widawsky's avatar
    drm/i915: Do remaps for all contexts · 3ccfd19d
    Ben Widawsky authored
    On both Ivybridge and Haswell, row remapping information is saved and
    restored with context. This means, we never actually properly supported
    the l3 remapping because our sysfs interface is asynchronous (and not
    tied to any context), and the known faulty HW would be reused by the
    next context to run.
    
    Not that due to the asynchronous nature of the sysfs entry, there is no
    point modifying the registers for the existing context. Instead we set a
    flag for all contexts to load the correct remapping information on the
    next run. Interested clients can use debugfs to determine whether or not
    the row has been remapped.
    
    One could propose at this point that we just do the remapping in the
    kernel. I guess since we have to maintain the sysfs interface anyway,
    I'm not sure how useful it is, and I do like keeping the policy in
    userspace; (it wasn't my original decision to make the
    interface the way it is, so I'm not attached).
    
    v2: Force a context switch when we have a remap on the next switch.
    (Ville)
    Don't let userspace use the interface with disabled contexts.
    
    v3: Don't force a context switch, just let it nop
    Improper context slice remap initialization, 1<<1 instead of 1<<i, but I
    rewrote it to avoid a second round of confusion.
    Error print moved to error path (All Ville)
    Added a comment on why the slice remap initialization happens.
    
    CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
    Signed-off-by: default avatarBen Widawsky <ben@bwidawsk.net>
    Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
    Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    3ccfd19d
i915_debugfs.c 61.8 KB