/*
 * Copyright (C) 2006 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Authors: 	Shlomi Gridish <gridish@freescale.com>
 * 		Li Yang <leoli@freescale.com>
 *
 * Description:
 * Internal header file for UCC unit routines.
 *
 * 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.
 */
#ifndef __UCC_H__
#define __UCC_H__

#include <soc/fsl/qe/immap_qe.h>
#include <soc/fsl/qe/qe.h>

#define STATISTICS

#define UCC_MAX_NUM	8

/* Slow or fast type for UCCs.
*/
enum ucc_speed_type {
	UCC_SPEED_TYPE_FAST = UCC_GUEMR_MODE_FAST_RX | UCC_GUEMR_MODE_FAST_TX,
	UCC_SPEED_TYPE_SLOW = UCC_GUEMR_MODE_SLOW_RX | UCC_GUEMR_MODE_SLOW_TX
};

/* ucc_set_type
 * Sets UCC to slow or fast mode.
 *
 * ucc_num - (In) number of UCC (0-7).
 * speed   - (In) slow or fast mode for UCC.
 */
int ucc_set_type(unsigned int ucc_num, enum ucc_speed_type speed);

int ucc_set_qe_mux_mii_mng(unsigned int ucc_num);

int ucc_set_qe_mux_rxtx(unsigned int ucc_num, enum qe_clock clock,
	enum comm_dir mode);
int ucc_set_tdm_rxtx_clk(unsigned int tdm_num, enum qe_clock clock,
			 enum comm_dir mode);
int ucc_set_tdm_rxtx_sync(unsigned int tdm_num, enum qe_clock clock,
			  enum comm_dir mode);

int ucc_mux_set_grant_tsa_bkpt(unsigned int ucc_num, int set, u32 mask);

/* QE MUX clock routing for UCC
*/
static inline int ucc_set_qe_mux_grant(unsigned int ucc_num, int set)
{
	return ucc_mux_set_grant_tsa_bkpt(ucc_num, set, QE_CMXUCR_GRANT);
}

static inline int ucc_set_qe_mux_tsa(unsigned int ucc_num, int set)
{
	return ucc_mux_set_grant_tsa_bkpt(ucc_num, set, QE_CMXUCR_TSA);
}

static inline int ucc_set_qe_mux_bkpt(unsigned int ucc_num, int set)
{
	return ucc_mux_set_grant_tsa_bkpt(ucc_num, set, QE_CMXUCR_BKPT);
}

#endif				/* __UCC_H__ */
ctive' href='/cgit.cgi/linux/net-next.git/commit/include/soc/fsl/qe/ucc_slow.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/include/soc/fsl/qe/ucc_slow.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/include/soc/fsl/qe/ucc_slow.h'>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/soc?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>soc</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/soc/fsl?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>fsl</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/soc/fsl/qe?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>qe</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/soc/fsl/qe/ucc_slow.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>ucc_slow.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='39cb2c9a316e77f6dfba96c543e55b6672d5a37e'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>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/soc/fsl/qe/ucc_slow.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/soc/fsl/qe/ucc_slow.h?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/soc/fsl/qe/ucc_slow.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>include/soc/fsl/qe/ucc_slow.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/soc/fsl/qe/ucc_slow.h?id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/soc/fsl/qe/ucc_slow.h?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/soc/fsl/qe/ucc_slow.h')</div><table summary='diffstat' class='diffstat'>