https://github.com/torvalds/linux
Revision 664a84d2c77cbff2945ed7f96d08afbba42b6293 authored by Ville Syrjälä on 13 May 2016, 17:53:56 UTC, committed by Jani Nikula on 29 June 2016, 08:16:17 UTC
During hibernation the cached DP port register value will be left with whatever value we have there when we create the hibernation image. Currently that means the port (and eDP PLL) will be off in the cached value. However when we resume there is no guarantee that the value in the actual register will match the cached value. If i915 isn't loaded in the kernel that loads the hibernation image, the port may well be on (eg. left on by the BIOS). The encoder state readout does the right thing in this case and updates our encoder state to reflect the actual hardware state. However the post-resume modeset will then use the stale cached port register value in intel_dp_link_down() and potentially confuse the hardware. This was caught by the following assert WARNING: CPU: 3 PID: 5288 at ../drivers/gpu/drm/i915/intel_dp.c:2184 assert_edp_pll+0x99/0xa0 [i915] eDP PLL state assertion failure (expected on, current off) on account of the eDP PLL getting prematurely turned off when shutting down the port, since the DP_PLL_ENABLE bit wasn't set in the cached register value. Presumably I introduced this problem in commit 6fec76628333 ("drm/i915: Use intel_dp->DP in eDP PLL setup") as before that we didn't update the cached value after shuttting the port down. That's assuming the port got enabled at least once prior to hibernating. If that didn't happen then the cached value would still have been totally out of sync with reality (eg. first boot w/o eDP on, then hibernate, and then resume with eDP on). So, let's fix this properly and refresh the cached register value from the hardware register during resume. DDI platforms shouldn't use the cached value during port disable at least, so shouldn't have this particular issue. They might still have issues if we skip the initial modeset and then try to retrain the link or something. But untangling this DP vs. DDI mess is a bigger topic, so let's jut punt on DDI for now. Cc: Jani Nikula <jani.nikula@intel.com> Cc: stable@vger.kernel.org Fixes: 6fec76628333 ("drm/i915: Use intel_dp->DP in eDP PLL setup") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1463162036-27931-1-git-send-email-ville.syrjala@linux.intel.com Reviewed-by: Imre Deak <imre.deak@intel.com> (cherry picked from commit 64989ca4b27acb026b6496ec21e43bee66f86a5b) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
1 parent 4c2e07c
Tip revision: 664a84d2c77cbff2945ed7f96d08afbba42b6293 authored by Ville Syrjälä on 13 May 2016, 17:53:56 UTC
drm/i915: Refresh cached DP port register value on resume
drm/i915: Refresh cached DP port register value on resume
Tip revision: 664a84d
atomic64_test.c
/*
* Testsuite for atomic64_t functions
*
* Copyright © 2010 Luca Barbieri
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/atomic.h>
#ifdef CONFIG_X86
#include <asm/cpufeature.h> /* for boot_cpu_has below */
#endif
#define TEST(bit, op, c_op, val) \
do { \
atomic##bit##_set(&v, v0); \
r = v0; \
atomic##bit##_##op(val, &v); \
r c_op val; \
WARN(atomic##bit##_read(&v) != r, "%Lx != %Lx\n", \
(unsigned long long)atomic##bit##_read(&v), \
(unsigned long long)r); \
} while (0)
/*
* Test for a atomic operation family,
* @test should be a macro accepting parameters (bit, op, ...)
*/
#define FAMILY_TEST(test, bit, op, args...) \
do { \
test(bit, op, ##args); \
test(bit, op##_acquire, ##args); \
test(bit, op##_release, ##args); \
test(bit, op##_relaxed, ##args); \
} while (0)
#define TEST_RETURN(bit, op, c_op, val) \
do { \
atomic##bit##_set(&v, v0); \
r = v0; \
r c_op val; \
BUG_ON(atomic##bit##_##op(val, &v) != r); \
BUG_ON(atomic##bit##_read(&v) != r); \
} while (0)
#define RETURN_FAMILY_TEST(bit, op, c_op, val) \
do { \
FAMILY_TEST(TEST_RETURN, bit, op, c_op, val); \
} while (0)
#define TEST_ARGS(bit, op, init, ret, expect, args...) \
do { \
atomic##bit##_set(&v, init); \
BUG_ON(atomic##bit##_##op(&v, ##args) != ret); \
BUG_ON(atomic##bit##_read(&v) != expect); \
} while (0)
#define XCHG_FAMILY_TEST(bit, init, new) \
do { \
FAMILY_TEST(TEST_ARGS, bit, xchg, init, init, new, new); \
} while (0)
#define CMPXCHG_FAMILY_TEST(bit, init, new, wrong) \
do { \
FAMILY_TEST(TEST_ARGS, bit, cmpxchg, \
init, init, new, init, new); \
FAMILY_TEST(TEST_ARGS, bit, cmpxchg, \
init, init, init, wrong, new); \
} while (0)
#define INC_RETURN_FAMILY_TEST(bit, i) \
do { \
FAMILY_TEST(TEST_ARGS, bit, inc_return, \
i, (i) + one, (i) + one); \
} while (0)
#define DEC_RETURN_FAMILY_TEST(bit, i) \
do { \
FAMILY_TEST(TEST_ARGS, bit, dec_return, \
i, (i) - one, (i) - one); \
} while (0)
static __init void test_atomic(void)
{
int v0 = 0xaaa31337;
int v1 = 0xdeadbeef;
int onestwos = 0x11112222;
int one = 1;
atomic_t v;
int r;
TEST(, add, +=, onestwos);
TEST(, add, +=, -one);
TEST(, sub, -=, onestwos);
TEST(, sub, -=, -one);
TEST(, or, |=, v1);
TEST(, and, &=, v1);
TEST(, xor, ^=, v1);
TEST(, andnot, &= ~, v1);
RETURN_FAMILY_TEST(, add_return, +=, onestwos);
RETURN_FAMILY_TEST(, add_return, +=, -one);
RETURN_FAMILY_TEST(, sub_return, -=, onestwos);
RETURN_FAMILY_TEST(, sub_return, -=, -one);
INC_RETURN_FAMILY_TEST(, v0);
DEC_RETURN_FAMILY_TEST(, v0);
XCHG_FAMILY_TEST(, v0, v1);
CMPXCHG_FAMILY_TEST(, v0, v1, onestwos);
}
#define INIT(c) do { atomic64_set(&v, c); r = c; } while (0)
static __init void test_atomic64(void)
{
long long v0 = 0xaaa31337c001d00dLL;
long long v1 = 0xdeadbeefdeafcafeLL;
long long v2 = 0xfaceabadf00df001LL;
long long onestwos = 0x1111111122222222LL;
long long one = 1LL;
atomic64_t v = ATOMIC64_INIT(v0);
long long r = v0;
BUG_ON(v.counter != r);
atomic64_set(&v, v1);
r = v1;
BUG_ON(v.counter != r);
BUG_ON(atomic64_read(&v) != r);
TEST(64, add, +=, onestwos);
TEST(64, add, +=, -one);
TEST(64, sub, -=, onestwos);
TEST(64, sub, -=, -one);
TEST(64, or, |=, v1);
TEST(64, and, &=, v1);
TEST(64, xor, ^=, v1);
TEST(64, andnot, &= ~, v1);
RETURN_FAMILY_TEST(64, add_return, +=, onestwos);
RETURN_FAMILY_TEST(64, add_return, +=, -one);
RETURN_FAMILY_TEST(64, sub_return, -=, onestwos);
RETURN_FAMILY_TEST(64, sub_return, -=, -one);
INIT(v0);
atomic64_inc(&v);
r += one;
BUG_ON(v.counter != r);
INIT(v0);
atomic64_dec(&v);
r -= one;
BUG_ON(v.counter != r);
INC_RETURN_FAMILY_TEST(64, v0);
DEC_RETURN_FAMILY_TEST(64, v0);
XCHG_FAMILY_TEST(64, v0, v1);
CMPXCHG_FAMILY_TEST(64, v0, v1, v2);
INIT(v0);
BUG_ON(atomic64_add_unless(&v, one, v0));
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(!atomic64_add_unless(&v, one, v1));
r += one;
BUG_ON(v.counter != r);
#ifdef CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
INIT(onestwos);
BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
r -= one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_dec_if_positive(&v) != -one);
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(atomic64_dec_if_positive(&v) != (-one - one));
BUG_ON(v.counter != r);
#else
#warning Please implement atomic64_dec_if_positive for your architecture and select the above Kconfig symbol
#endif
INIT(onestwos);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_inc_not_zero(&v));
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
}
static __init int test_atomics(void)
{
test_atomic();
test_atomic64();
#ifdef CONFIG_X86
pr_info("passed for %s platform %s CX8 and %s SSE\n",
#ifdef CONFIG_X86_64
"x86-64",
#elif defined(CONFIG_X86_CMPXCHG64)
"i586+",
#else
"i386+",
#endif
boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without",
boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without");
#else
pr_info("passed\n");
#endif
return 0;
}
core_initcall(test_atomics);
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