/*********************************************************************
 *                
 * Filename:      irmod.h
 * Version:       0.3
 * Description:   IrDA module and utilities functions
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Mon Dec 15 13:58:52 1997
 * Modified at:   Fri Jan 28 13:15:24 2000
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1998-2000 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 2000-2002 Jean Tourrilhes <jt@hpl.hp.com>
 *      
 *     This program is free software; you can redistribute it and/or 
 *     modify it under the terms of the GNU General Public License as 
 *     published by the Free Software Foundation; either version 2 of 
 *     the License, or (at your option) any later version.
 *  
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is 
 *     provided "AS-IS" and at no charg.
 *     
 ********************************************************************/

#ifndef IRMOD_H
#define IRMOD_H

/* Misc status information */
typedef enum {
	STATUS_OK,
	STATUS_ABORTED,
	STATUS_NO_ACTIVITY,
	STATUS_NOISY,
	STATUS_REMOTE,
} LINK_STATUS;

typedef enum {
	LOCK_NO_CHANGE,
	LOCK_LOCKED,
	LOCK_UNLOCKED,
} LOCK_STATUS;

typedef enum { FLOW_STOP, FLOW_START } LOCAL_FLOW;

/*  
 *  IrLMP disconnect reasons. The order is very important, since they 
 *  correspond to disconnect reasons sent in IrLMP disconnect frames, so
 *  please do not touch :-)
 */
typedef enum {
	LM_USER_REQUEST = 1,  /* User request */
	LM_LAP_DISCONNECT,    /* Unexpected IrLAP disconnect */
	LM_CONNECT_FAILURE,   /* Failed to establish IrLAP connection */
	LM_LAP_RESET,         /* IrLAP reset */
	LM_INIT_DISCONNECT,   /* Link Management initiated disconnect */
	LM_LSAP_NOTCONN,      /* Data delivered on unconnected LSAP */
	LM_NON_RESP_CLIENT,   /* Non responsive LM-MUX client */
	LM_NO_AVAIL_CLIENT,   /* No available LM-MUX client */
	LM_CONN_HALF_OPEN,    /* Connection is half open */
	LM_BAD_SOURCE_ADDR,   /* Illegal source address (i.e 0x00) */
} LM_REASON;
#define LM_UNKNOWN 0xff       /* Unspecified disconnect reason */

/* A few forward declarations (to make compiler happy) */
struct qos_info;		/* in <net/irda/qos.h> */

/*
 *  Notify structure used between transport and link management layers
 */
typedef struct {
	int (*data_indication)(void *priv, void *sap, struct sk_buff *skb);
	int (*udata_indication)(void *priv, void *sap, struct sk_buff *skb);
	void (*connect_confirm)(void *instance, void *sap, 
				struct qos_info *qos, __u32 max_sdu_size,
				__u8 max_header_size, struct sk_buff *skb);
	void (*connect_indication)(void *instance, void *sap, 
				   struct qos_info *qos, __u32 max_sdu_size, 
				   __u8 max_header_size, struct sk_buff *skb);
	void (*disconnect_indication)(void *instance, void *sap, 
				      LM_REASON reason, struct sk_buff *);
	void (*flow_indication)(void *instance, void *sap, LOCAL_FLOW flow);
	void (*status_indication)(void *instance,
				  LINK_STATUS link, LOCK_STATUS lock);
	void *instance; /* Layer instance pointer */
	char name[16];  /* Name of layer */
} notify_t;

#define NOTIFY_MAX_NAME 16

/* Zero the notify structure */
void irda_notify_init(notify_t *notify);

/* Locking wrapper - Note the inverted logic on irda_lock().
 * Those function basically return false if the lock is already in the
 * position you want to set it. - Jean II */
#define irda_lock(lock)		(! test_and_set_bit(0, (void *) (lock)))
#define irda_unlock(lock)	(test_and_clear_bit(0, (void *) (lock)))

#endif /* IRMOD_H */









7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/phy?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/dt-bindings/phy?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/dt-bindings/phy?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>include/dt-bindings/phy</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/phy?id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings/phy?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e&amp;id2=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>diff</a>)</td></tr></table>
<div class='commit-subject'>drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()</div><div class='commit-msg'>I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.

It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server.  The call chains were different:

 - VT ioctl(KDSETMODE, KD_TEXT):

    intel_cleanup_plane_fb+0x5b/0xa0 [i915]
    drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
    intel_atomic_commit_tail+0x749/0xfe0 [i915]
    intel_atomic_commit+0x3cb/0x4f0 [i915]
    drm_atomic_commit+0x4b/0x50 [drm]
    restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
    drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
    drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
    intel_fbdev_set_par+0x18/0x70 [i915]
    fb_set_var+0x236/0x460
    fbcon_blank+0x30f/0x350
    do_unblank_screen+0xd2/0x1a0
    vt_ioctl+0x507/0x12a0
    tty_ioctl+0x355/0xc30
    do_vfs_ioctl+0xa3/0x5e0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x13/0x94

 - i915 unpin_work workqueue:

    intel_unpin_work_fn+0x58/0x140 [i915]
    process_one_work+0x1f1/0x480
    worker_thread+0x48/0x4d0
    kthread+0x101/0x140

and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.

Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.

[ Reported it originally to the i915 developers on Jan 8, applying the
  ugly workaround on my own now after triggering the problem for the
  second time with no feedback.

  This is likely to be the same bug reported as

     https://bugs.freedesktop.org/show_bug.cgi?id=98829
     https://bugs.freedesktop.org/show_bug.cgi?id=99134

  which has a patch for the underlying problem, but it hasn't gotten to
  me, so I'm applying the workaround. ]

Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'include/dt-bindings/phy')</div><table summary='diffstat' class='diffstat'>