drm/i915: destroy connector sysfs files earlier
authorPaulo Zanoni <paulo.r.zanoni@intel.com>
Thu, 26 Sep 2013 23:05:59 +0000 (20:05 -0300)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 1 Oct 2013 05:45:48 +0000 (07:45 +0200)
commitd9255d57147e1dbcebdf6670409c2fa0ac3609e6
tree11d46c5f18f5f9432cb55a11795d33430b753b5c
parent70aff66c953054334bf0569696901c13e206ade6
drm/i915: destroy connector sysfs files earlier

For some reason, every single time I try to run module_reload
something tries to read the connector sysfs files. This happens
after we destroy the encoders and before we destroy the connectors, so
when the sysfs read triggers the connector detect() function,
intel_conector->encoder points to memory that was already freed.

The bad backtrace is just:
    [<ffffffff8163ca9a>] dump_stack+0x54/0x74
    [<ffffffffa00c2c8e>] intel_dp_detect+0x1e/0x4b0 [i915]
    [<ffffffffa001913d>] status_show+0x3d/0x80 [drm]
    [<ffffffff813d5340>] dev_attr_show+0x20/0x60
    [<ffffffff81221f50>] ? sysfs_read_file+0x80/0x1b0
    [<ffffffff81221f79>] sysfs_read_file+0xa9/0x1b0
    [<ffffffff811aaf1e>] vfs_read+0x9e/0x170
    [<ffffffff811aba4c>] SyS_read+0x4c/0xa0
    [<ffffffff8164e392>] system_call_fastpath+0x16/0x1b

But if you add tons of memory checking debug options to your Kernel
you'll also see:
 - general protection fault: 0000
 - BUG kmalloc-4096 (Tainted: G      D W   ): Poison overwritten
 - INFO: Allocated in intel_ddi_init+0x65/0x270 [i915]
 - INFO: Freed in intel_dp_encoder_destroy+0x69/0xb0 [i915]
Among a bunch of other error messages.

So this commit just destroys the sysfs files before both the encoder
and connectors are freed.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_crt.c
drivers/gpu/drm/i915/intel_display.c
drivers/gpu/drm/i915/intel_dp.c
drivers/gpu/drm/i915/intel_dsi.c
drivers/gpu/drm/i915/intel_dvo.c
drivers/gpu/drm/i915/intel_hdmi.c
drivers/gpu/drm/i915/intel_lvds.c
drivers/gpu/drm/i915/intel_sdvo.c
drivers/gpu/drm/i915/intel_tv.c