• Paulo Zanoni's avatar
    drm/i915: destroy connector sysfs files earlier · d9255d57
    Paulo Zanoni authored
    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: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
    Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    d9255d57
intel_dsi.c 17.9 KB