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1a72d65d62
When removing of the BKL the locking around lastclose() was rearranged and resulted in the holding of the open_count spinlock over the call into drm_lastclose(). The drivers were not ready for this path to be atomic - it may indeed involve long waits to release old objects and cleanup the GPU - and so we ended up scheduling whilst atomic. [ 54.625598] BUG: scheduling while atomic: X/3546/0x00000002 [ 54.625600] Modules linked in: sco bridge stp llc input_polldev rfcomm bnep l2cap crc16 sch_sfq ipv6 md_mod acpi_cpufreq mperf cryptd aes_x86_64 aes_generic xts gf128mul dm_crypt dm_mod btusb bluetooth usbhid hid zaurus cdc_ether usbnet mii cdc_wdm cdc_acm uvcvideo videodev v4l1_compat v4l2_compat_ioctl32 snd_hda_codec_conexant arc4 pcmcia ecb snd_hda_intel joydev sdhci_pci sdhci snd_hda_codec tpm_tis firewire_ohci mmc_core e1000e uhci_hcd thinkpad_acpi nvram yenta_socket pcmcia_rsrc pcmcia_core tpm wmi sr_mod firewire_core iwlagn ehci_hcd snd_hwdep snd_pcm usbcore tpm_bios thermal led_class snd_timer iwlcore snd soundcore ac snd_page_alloc pcspkr psmouse serio_raw battery sg mac80211 evdev cfg80211 i2c_i801 iTCO_wdt iTCO_vendor_support cdrom processor crc_itu_t rfkill xfs exportfs sd_mod crc_t10dif ahci libahci libata scsi_mod [last unloaded: scsi_wait_scan] [ 54.625663] Pid: 3546, comm: X Not tainted 2.6.35-04771-g1787985 #301 [ 54.625665] Call Trace: [ 54.625671] [<ffffffff8102d599>] __schedule_bug+0x57/0x5c [ 54.625675] [<ffffffff81384141>] schedule+0xe5/0x832 [ 54.625679] [<ffffffff81163e77>] ? put_dec+0x20/0x3c [ 54.625682] [<ffffffff81384dd4>] schedule_timeout+0x275/0x29f [ 54.625686] [<ffffffff810455e1>] ? process_timeout+0x0/0xb [ 54.625688] [<ffffffff81384e17>] schedule_timeout_uninterruptible+0x19/0x1b [ 54.625691] [<ffffffff81045893>] msleep+0x16/0x1d [ 54.625695] [<ffffffff812a2e53>] i9xx_crtc_dpms+0x273/0x2ae [ 54.625698] [<ffffffff812a18be>] intel_crtc_dpms+0x28/0xe7 [ 54.625702] [<ffffffff811ec0fa>] drm_helper_disable_unused_functions+0xf0/0x118 [ 54.625705] [<ffffffff811ecde3>] drm_crtc_helper_set_config+0x644/0x7c8 [ 54.625708] [<ffffffff811f12dd>] ? drm_copy_field+0x40/0x50 [ 54.625711] [<ffffffff811ebca2>] drm_fb_helper_force_kernel_mode+0x3e/0x85 [ 54.625713] [<ffffffff811ebcf2>] drm_fb_helper_restore+0x9/0x24 [ 54.625717] [<ffffffff81290a41>] i915_driver_lastclose+0x2b/0x5c [ 54.625720] [<ffffffff811f14a7>] drm_lastclose+0x44/0x2ad [ 54.625722] [<ffffffff811f1ed2>] drm_release+0x5c6/0x609 [ 54.625726] [<ffffffff810d1275>] fput+0x109/0x1c7 [ 54.625728] [<ffffffff810ce5e4>] filp_close+0x61/0x6b [ 54.625731] [<ffffffff810ce680>] sys_close+0x92/0xd4 [ 54.625734] [<ffffffff81002a2b>] system_call_fastpath+0x16/0x1b v2: The spinlock is actually superfluous as access to open_count is entirely serialised by drm_global_mutex and so can be dropped. The count_lock spinlock instead appears to be used to protect access to dev->buf_alloc and dev->buf_use. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Dave Airlie <airlied@redhat.com> |
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|---|---|---|
| .. | ||
| i2c | ||
| i810 | ||
| i830 | ||
| i915 | ||
| mga | ||
| nouveau | ||
| r128 | ||
| radeon | ||
| savage | ||
| sis | ||
| tdfx | ||
| ttm | ||
| via | ||
| vmwgfx | ||
| ati_pcigart.c | ||
| drm_agpsupport.c | ||
| drm_auth.c | ||
| drm_buffer.c | ||
| drm_bufs.c | ||
| drm_cache.c | ||
| drm_context.c | ||
| drm_crtc.c | ||
| drm_crtc_helper.c | ||
| drm_debugfs.c | ||
| drm_dma.c | ||
| drm_dp_i2c_helper.c | ||
| drm_drawable.c | ||
| drm_drv.c | ||
| drm_edid.c | ||
| drm_edid_modes.h | ||
| drm_encoder_slave.c | ||
| drm_fb_helper.c | ||
| drm_fops.c | ||
| drm_gem.c | ||
| drm_global.c | ||
| drm_hashtab.c | ||
| drm_info.c | ||
| drm_ioc32.c | ||
| drm_ioctl.c | ||
| drm_irq.c | ||
| drm_lock.c | ||
| drm_memory.c | ||
| drm_mm.c | ||
| drm_modes.c | ||
| drm_pci.c | ||
| drm_platform.c | ||
| drm_proc.c | ||
| drm_scatter.c | ||
| drm_sman.c | ||
| drm_stub.c | ||
| drm_sysfs.c | ||
| drm_trace.h | ||
| drm_trace_points.c | ||
| drm_vm.c | ||
| Kconfig | ||
| Makefile | ||
| README.drm | ||
************************************************************
* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html