loader: add dri_driver option to override dri driver to load

drirc implementation of MESA_LOADER_DRIVER_OVERRIDE which can be
used to override dri driver to load.

Usage:

override dri driver for device with spec kernel driver name:

<device kernel_driver="kernel_driver_name">
  <option name="dri_driver" value="new_dri_driver" />
</device>

or

<device driver="loader" kernel_driver="kernel_driver_name">
  <option name="dri_driver" value="new_dri_driver" />
</device>

v2:
  add kernel_driver device attribute to specify kernel
  driver name instead of reuse driver attribute

v3:
  seperate loader_get_kernel_driver_name into another patch
  seperate add kernel_driver attribute into another patch

Suggested-by: Michel Dänzer <[email protected]>
Signed-off-by: Qiang Yu <[email protected]>
Acked-by: Michel Dänzer <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>
[v4 Emil: add HAVE_LIBDRM guard around __driConfigOptionsLoader and
loader_get_dri_config_driver]
Signed-off-by: Emil Velikov <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/util/xmlpool/t_options.h b/src/util/xmlpool/t_options.h
index f0537e965b8..d4881b334e1 100644
--- a/src/util/xmlpool/t_options.h
+++ b/src/util/xmlpool/t_options.h
@@ -411,6 +411,11 @@ DRI_CONF_OPT_BEGIN(device_id, string, def) \
         DRI_CONF_DESC(en,gettext("Define the graphic device to use if possible")) \
 DRI_CONF_OPT_END
 
+#define DRI_CONF_DRI_DRIVER(def) \
+DRI_CONF_OPT_BEGIN(dri_driver, string, def) \
+        DRI_CONF_DESC(en,gettext("Override the DRI driver to load")) \
+DRI_CONF_OPT_END
+
 /**
  * \brief Gallium-Nine specific configuration options
  */