DragonFly On-Line Manual Pages

Search: Section:  

RADEON(4)             DragonFly Kernel Interfaces Manual             RADEON(4)


NAME

     radeon - Driver for AMD/ATI Radeon graphics chipsets


DESCRIPTION

     The radeon driver provides support for the AMD Radeon graphics chips.
     Please refer the Loader Tunables section in syscons(4) for more
     information about how to make the console work with radeon.


LOADER TUNABLES

     Tunables can be set at the loader(8) prompt before booting the kernel or
     stored in loader.conf(5).

     drm.radeon.no_wb
             Disables AGP writeback for scratch registers.

     drm.radeon.dynclks
             Enable/Disable dynamic clocks

     drm.radeon.msi
             Enable/Disable MSI (message signaled interrupts) 1 = enable, 0 =
             disable, -1 = auto (default)

     drm.radeon.fastfb
             Direct FB access for IGP chips, which can significantly improve
             performance for some applications.  This option only affects the
             RS690, RS780 and RS880 chipsets, and only when no sideport memory
             is available.  1 = enable, 0 = disable (default)

     drm.radeon.dpm
             DPM (dynamic power management) support.  1 = enable, 0 = disable,
             -1 = auto (default)

     drm.radeon.backlight
             Backlight support.  1 = enable, 0 = disable, -1 = auto (default)


SYSCTL VARIABLES

     If display backlight level can be controlled by the GPU (which is often
     the case in notebooks), the sysctl hw.backlight_level can be used to
     adjust the backlight level.  Permitted values are from 0 to the value
     returned from the hw.backlight_max sysctl.  On older Radeon GPU models
     than the R600 series, the hw.backlight_level and hw.backlight_max sysctl
     variables are no longer available by default.  Setting the
     drm.radeon.backlight tunable to "1" will force-enable native backlight
     control via the sysctl variables in this case.


SEE ALSO

     drm(4), syscons(4)


HISTORY

     The radeon driver was first available for Linux.


BUGS

     Enabling drm.radeon.fastfb on RS690 chipsets can cause graphics
     corruption when hardware acceleration is used.  Display backlight control
     with the hw.backlight_level sysctl is only supported for chipsets using
     AtomBIOS (which includes some R400 chipsets and all later generations).

DragonFly 5.7-DEVELOPMENT       October 9, 2019      DragonFly 5.7-DEVELOPMENT

Search: Section: