1. 30 Sep, 2015 35 commits
  2. 21 Sep, 2015 2 commits
    • Jonathon Jongsma's avatar
      drm/qxl: validate monitors config modes · 93401d9f
      Jonathon Jongsma authored
      commit bd3e1c7c upstream.
      
      Due to some recent changes in
      drm_helper_probe_single_connector_modes_merge_bits(), old custom modes
      were not being pruned properly. In current kernels,
      drm_mode_validate_basic() is called to sanity-check each mode in the
      list. If the sanity-check passes, the mode's status gets set to to
      MODE_OK. In older kernels this check was not done, so old custom modes
      would still have a status of MODE_UNVERIFIED at this point, and would
      therefore be pruned later in the function.
      
      As a result of this new behavior, the list of modes for a device always
      includes every custom mode ever configured for the device, with the
      largest one listed first. Since desktop environments usually choose the
      first preferred mode when a hotplug event is emitted, this had the
      result of making it very difficult for the user to reduce the size of
      the display.
      
      The qxl driver did implement the mode_valid connector function, but it
      was empty. In order to restore the old behavior where old custom modes
      are pruned, we implement a proper mode_valid function for the qxl
      driver. This function now checks each mode against the last configured
      custom mode and the list of standard modes. If the mode doesn't match
      any of these, its status is set to MODE_BAD so that it will be pruned as
      expected.
      Signed-off-by: default avatarJonathon Jongsma <jjongsma@redhat.com>
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      93401d9f
    • Stephen Chandler Paul's avatar
      DRM - radeon: Don't link train DisplayPort on HPD until we get the dpcd · 3b895193
      Stephen Chandler Paul authored
      commit 924f92bf upstream.
      
      Most of the time this isn't an issue since hotplugging an adaptor will
      trigger a crtc mode change which in turn, causes the driver to probe
      every DisplayPort for a dpcd. However, in cases where hotplugging
      doesn't cause a mode change (specifically when one unplugs a monitor
      from a DisplayPort connector, then plugs that same monitor back in
      seconds later on the same port without any other monitors connected), we
      never probe for the dpcd before starting the initial link training. What
      happens from there looks like this:
      
      	- GPU has only one monitor connected. It's connected via
      	  DisplayPort, and does not go through an adaptor of any sort.
      
      	- User unplugs DisplayPort connector from GPU.
      
      	- Change in HPD is detected by the driver, we probe every
      	  DisplayPort for a possible connection.
      
      	- Probe the port the user originally had the monitor connected
      	  on for it's dpcd. This fails, and we clear the first (and only
      	  the first) byte of the dpcd to indicate we no longer have a
      	  dpcd for this port.
      
      	- User plugs the previously disconnected monitor back into the
      	  same DisplayPort.
      
      	- radeon_connector_hotplug() is called before everyone else,
      	  and tries to handle the link training. Since only the first
      	  byte of the dpcd is zeroed, the driver is able to complete
      	  link training but does so against the wrong dpcd, causing it
      	  to initialize the link with the wrong settings.
      
      	- Display stays blank (usually), dpcd is probed after the
      	  initial link training, and the driver prints no obvious
      	  messages to the log.
      
      In theory, since only one byte of the dpcd is chopped off (specifically,
      the byte that contains the revision information for DisplayPort), it's
      not entirely impossible that this bug may not show on certain monitors.
      For instance, the only reason this bug was visible on my ASUS PB238
      monitor was due to the fact that this monitor using the enhanced framing
      symbol sequence, the flag for which is ignored if the radeon driver
      thinks that the DisplayPort version is below 1.1.
      Signed-off-by: default avatarStephen Chandler Paul <cpaul@redhat.com>
      Reviewed-by: default avatarJerome Glisse <jglisse@redhat.com>
      Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      3b895193
  3. 18 Sep, 2015 3 commits