Commit db80066c authored by Jani Nikula's avatar Jani Nikula

drm/i915/params: prevent changing module params runtime

Only support runtime changes through the debugfs.

i915.verbose_state_checks remains an exception, and is not exposed via
debugfs.

This depends on IGT having been updated to use the debugfs for modifying
the parameters.

Cc: Juha-Pekka Heikkilä <juha-pekka.heikkila@intel.com>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Reviewed-by: default avatarJuha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200601215510.18379-3-jani.nikula@intel.com
parent f322e851
...@@ -40,6 +40,15 @@ struct i915_params i915_modparams __read_mostly = { ...@@ -40,6 +40,15 @@ struct i915_params i915_modparams __read_mostly = {
#undef MEMBER #undef MEMBER
}; };
/*
* Note: As a rule, keep module parameter sysfs permissions read-only
* 0400. Runtime changes are only supported through i915 debugfs.
*
* For any exceptions requiring write access and runtime changes through module
* parameter sysfs, prevent debugfs file creation by setting the parameter's
* debugfs mode to 0.
*/
i915_param_named(modeset, int, 0400, i915_param_named(modeset, int, 0400,
"Use kernel modesetting [KMS] (0=disable, " "Use kernel modesetting [KMS] (0=disable, "
"1=on, -1=force vga console preference [default])"); "1=on, -1=force vga console preference [default])");
...@@ -49,7 +58,7 @@ i915_param_named_unsafe(enable_dc, int, 0400, ...@@ -49,7 +58,7 @@ i915_param_named_unsafe(enable_dc, int, 0400,
"(-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6; " "(-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6; "
"3=up to DC5 with DC3CO; 4=up to DC6 with DC3CO)"); "3=up to DC5 with DC3CO; 4=up to DC6 with DC3CO)");
i915_param_named_unsafe(enable_fbc, int, 0600, i915_param_named_unsafe(enable_fbc, int, 0400,
"Enable frame buffer compression for power savings " "Enable frame buffer compression for power savings "
"(default: -1 (use per-chip default))"); "(default: -1 (use per-chip default))");
...@@ -57,7 +66,7 @@ i915_param_named_unsafe(lvds_channel_mode, int, 0400, ...@@ -57,7 +66,7 @@ i915_param_named_unsafe(lvds_channel_mode, int, 0400,
"Specify LVDS channel mode " "Specify LVDS channel mode "
"(0=probe BIOS [default], 1=single-channel, 2=dual-channel)"); "(0=probe BIOS [default], 1=single-channel, 2=dual-channel)");
i915_param_named_unsafe(panel_use_ssc, int, 0600, i915_param_named_unsafe(panel_use_ssc, int, 0400,
"Use Spread Spectrum Clock with panels [LVDS/eDP] " "Use Spread Spectrum Clock with panels [LVDS/eDP] "
"(default: auto from VBT)"); "(default: auto from VBT)");
...@@ -65,25 +74,25 @@ i915_param_named_unsafe(vbt_sdvo_panel_type, int, 0400, ...@@ -65,25 +74,25 @@ i915_param_named_unsafe(vbt_sdvo_panel_type, int, 0400,
"Override/Ignore selection of SDVO panel mode in the VBT " "Override/Ignore selection of SDVO panel mode in the VBT "
"(-2=ignore, -1=auto [default], index in VBT BIOS table)"); "(-2=ignore, -1=auto [default], index in VBT BIOS table)");
i915_param_named_unsafe(reset, int, 0600, i915_param_named_unsafe(reset, int, 0400,
"Attempt GPU resets (0=disabled, 1=full gpu reset, 2=engine reset [default])"); "Attempt GPU resets (0=disabled, 1=full gpu reset, 2=engine reset [default])");
i915_param_named_unsafe(vbt_firmware, charp, 0400, i915_param_named_unsafe(vbt_firmware, charp, 0400,
"Load VBT from specified file under /lib/firmware"); "Load VBT from specified file under /lib/firmware");
#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) #if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
i915_param_named(error_capture, bool, 0600, i915_param_named(error_capture, bool, 0400,
"Record the GPU state following a hang. " "Record the GPU state following a hang. "
"This information in /sys/class/drm/card<N>/error is vital for " "This information in /sys/class/drm/card<N>/error is vital for "
"triaging and debugging hangs."); "triaging and debugging hangs.");
#endif #endif
i915_param_named_unsafe(enable_hangcheck, bool, 0600, i915_param_named_unsafe(enable_hangcheck, bool, 0400,
"Periodically check GPU activity for detecting hangs. " "Periodically check GPU activity for detecting hangs. "
"WARNING: Disabling this can cause system wide hangs. " "WARNING: Disabling this can cause system wide hangs. "
"(default: true)"); "(default: true)");
i915_param_named_unsafe(enable_psr, int, 0600, i915_param_named_unsafe(enable_psr, int, 0400,
"Enable PSR " "Enable PSR "
"(0=disabled, 1=enabled) " "(0=disabled, 1=enabled) "
"Default: -1 (use per-chip default)"); "Default: -1 (use per-chip default)");
...@@ -96,22 +105,22 @@ i915_param_named_unsafe(disable_power_well, int, 0400, ...@@ -96,22 +105,22 @@ i915_param_named_unsafe(disable_power_well, int, 0400,
"Disable display power wells when possible " "Disable display power wells when possible "
"(-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)"); "(-1=auto [default], 0=power wells always on, 1=power wells disabled when possible)");
i915_param_named_unsafe(enable_ips, int, 0600, "Enable IPS (default: true)"); i915_param_named_unsafe(enable_ips, int, 0400, "Enable IPS (default: true)");
i915_param_named(fastboot, int, 0600, i915_param_named(fastboot, int, 0400,
"Try to skip unnecessary mode sets at boot time " "Try to skip unnecessary mode sets at boot time "
"(0=disabled, 1=enabled) " "(0=disabled, 1=enabled) "
"Default: -1 (use per-chip default)"); "Default: -1 (use per-chip default)");
i915_param_named_unsafe(load_detect_test, bool, 0600, i915_param_named_unsafe(load_detect_test, bool, 0400,
"Force-enable the VGA load detect code for testing (default:false). " "Force-enable the VGA load detect code for testing (default:false). "
"For developers only."); "For developers only.");
i915_param_named_unsafe(force_reset_modeset_test, bool, 0600, i915_param_named_unsafe(force_reset_modeset_test, bool, 0400,
"Force a modeset during gpu reset for testing (default:false). " "Force a modeset during gpu reset for testing (default:false). "
"For developers only."); "For developers only.");
i915_param_named_unsafe(invert_brightness, int, 0600, i915_param_named_unsafe(invert_brightness, int, 0400,
"Invert backlight brightness " "Invert backlight brightness "
"(-1 force normal, 0 machine defaults, 1 force inversion), please " "(-1 force normal, 0 machine defaults, 1 force inversion), please "
"report PCI device ID, subsystem vendor and subsystem device ID " "report PCI device ID, subsystem vendor and subsystem device ID "
...@@ -121,10 +130,11 @@ i915_param_named_unsafe(invert_brightness, int, 0600, ...@@ -121,10 +130,11 @@ i915_param_named_unsafe(invert_brightness, int, 0600,
i915_param_named(disable_display, bool, 0400, i915_param_named(disable_display, bool, 0400,
"Disable display (default: false)"); "Disable display (default: false)");
i915_param_named(mmio_debug, int, 0600, i915_param_named(mmio_debug, int, 0400,
"Enable the MMIO debug code for the first N failures (default: off). " "Enable the MMIO debug code for the first N failures (default: off). "
"This may negatively affect performance."); "This may negatively affect performance.");
/* Special case writable file */
i915_param_named(verbose_state_checks, bool, 0600, i915_param_named(verbose_state_checks, bool, 0600,
"Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions."); "Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions.");
...@@ -155,7 +165,7 @@ i915_param_named_unsafe(huc_firmware_path, charp, 0400, ...@@ -155,7 +165,7 @@ i915_param_named_unsafe(huc_firmware_path, charp, 0400,
i915_param_named_unsafe(dmc_firmware_path, charp, 0400, i915_param_named_unsafe(dmc_firmware_path, charp, 0400,
"DMC firmware path to use instead of the default one"); "DMC firmware path to use instead of the default one");
i915_param_named_unsafe(enable_dp_mst, bool, 0600, i915_param_named_unsafe(enable_dp_mst, bool, 0400,
"Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)"); "Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG) #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
...@@ -163,7 +173,7 @@ i915_param_named_unsafe(inject_probe_failure, uint, 0400, ...@@ -163,7 +173,7 @@ i915_param_named_unsafe(inject_probe_failure, uint, 0400,
"Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)"); "Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)");
#endif #endif
i915_param_named(enable_dpcd_backlight, int, 0600, i915_param_named(enable_dpcd_backlight, int, 0400,
"Enable support for DPCD backlight control" "Enable support for DPCD backlight control"
"(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enabled)"); "(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enabled)");
......
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