On Wed, 04 Jun 2014, David Herrmann <dh.herrmann@xxxxxxxxx> wrote: > Hi > > On Wed, Jun 4, 2014 at 12:57 AM, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: >> From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >> >> Touching the VGA resources on an IVB EFI machine causes hard hangs when >> we then kick out the efifb. Ouch. >> >> Apparently this also prevents unclaimed register errors on hsw and >> hard machine hangs on my i855gm when trying to unbind fbcon. >> >> Also, we want this to make I915_FBDEV=n safe. >> >> v2: Rebase and pimp commit message. >> >> v3: We also need to unregister the vga console, otherwise the unbind >> of the fb console before module unload might resurrect it again. >> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813 >> Cc: David Herrmann <dh.herrmann@xxxxxxxxx> >> Cc: Jean-Christophe Plagniol-Villard <plagnioj@xxxxxxxxxxxx> >> Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx> >> Cc: linux-fbdev@xxxxxxxxxxxxxxx >> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> (v1) >> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> >> --- >> drivers/gpu/drm/i915/i915_dma.c | 34 +++++++++++++++++++++++++++++++++- >> drivers/video/console/dummycon.c | 1 + >> drivers/video/console/vgacon.c | 1 + >> 3 files changed, 35 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c >> index b9159ade5e85..a4df80740b37 100644 >> --- a/drivers/gpu/drm/i915/i915_dma.c >> +++ b/drivers/gpu/drm/i915/i915_dma.c >> @@ -36,6 +36,8 @@ >> #include "i915_drv.h" >> #include "i915_trace.h" >> #include <linux/pci.h> >> +#include <linux/console.h> >> +#include <linux/vt.h> >> #include <linux/vgaarb.h> >> #include <linux/acpi.h> >> #include <linux/pnp.h> >> @@ -1450,6 +1452,29 @@ static void i915_kick_out_firmware_fb(struct drm_i915_private *dev_priv) >> } >> #endif >> >> +static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv) >> +{ >> +#if !defined(CONFIG_VGA_CONSOLE) >> + return 0; >> +#else >> + int ret; >> + >> +#if !defined(CONFIG_DUMMY_CONSOLE) >> + return -ENODEV; >> +#endif >> + >> + DRM_INFO("Replacing VGA console driver\n"); >> + >> + console_lock(); >> + ret = do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES - 1, 1); > > You rely on compiler-optimizations here. "dummy_con" is not available > if !CONFIG_DUMMY_CONSOLE, but you use it. This causes linker-failure > if dead-code elimination is not done (-O0). Nested #ifs too. How about #if !defined(CONFIG_VGA_CONSOLE) static inline int i915_kick_out_vgacon(struct drm_i915_private *dev_priv) { return 0; } #elif !defined(CONFIG_DUMMY_CONSOLE) static inline int i915_kick_out_vgacon(struct drm_i915_private *dev_priv) { return -ENODEV; } #else static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv) { /* ... */ } #endif in proper kernel style? BR, Jani. > > Thanks > David > >> + if (ret == 0) >> + ret = do_unregister_con_driver(&vga_con); >> + console_unlock(); >> + >> + return ret; >> +#endif >> +} >> + >> static void i915_dump_device_info(struct drm_i915_private *dev_priv) >> { >> const struct intel_device_info *info = &dev_priv->info; >> @@ -1623,8 +1648,15 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags) >> if (ret) >> goto out_regs; >> >> - if (drm_core_check_feature(dev, DRIVER_MODESET)) >> + if (drm_core_check_feature(dev, DRIVER_MODESET)) { >> + ret = i915_kick_out_vgacon(dev_priv); >> + if (ret) { >> + DRM_ERROR("failed to remove conflicting VGA console\n"); >> + goto out_gtt; >> + } >> + >> i915_kick_out_firmware_fb(dev_priv); >> + } >> >> pci_set_master(dev->pdev); >> >> diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c >> index b63860f7beab..40bec8d64b0a 100644 >> --- a/drivers/video/console/dummycon.c >> +++ b/drivers/video/console/dummycon.c >> @@ -77,3 +77,4 @@ const struct consw dummy_con = { >> .con_set_palette = DUMMY, >> .con_scrolldelta = DUMMY, >> }; >> +EXPORT_SYMBOL_GPL(dummy_con); >> diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c >> index 9d8feac67637..84acd6223dc5 100644 >> --- a/drivers/video/console/vgacon.c >> +++ b/drivers/video/console/vgacon.c >> @@ -1440,5 +1440,6 @@ const struct consw vga_con = { >> .con_build_attr = vgacon_build_attr, >> .con_invert_region = vgacon_invert_region, >> }; >> +EXPORT_SYMBOL(vga_con); >> >> MODULE_LICENSE("GPL"); >> -- >> 1.8.1.4 >> > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
