6.6-stable review patch. If anyone has any objections, please let me know.
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From: Xin Li (Intel) xin@zytor.com
[ Upstream commit 9cb15478916e849d62a6ec44b10c593b9663328c ]
Due to a problem in the iTBT DP-in adapter's firmware the sink on a TBT link may get disconnected inadvertently if the SINK_COUNT_ESI and the DP_LINK_SERVICE_IRQ_VECTOR_ESI0 registers are read in a single AUX transaction. Work around the issue by reading these registers in separate transactions.
The issue affects MTL+ platforms and will be fixed in the DP-in adapter firmware, however releasing that firmware fix may take some time and is not guaranteed to be available for all systems. Based on this apply the workaround on affected platforms.
See HSD #13013007775.
v2: Cc'ing Mika Westerberg.
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13760 Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14147 Cc: Mika Westerberg mika.westerberg@linux.intel.com Cc: stable@vger.kernel.org Reviewed-by: Mika Westerberg mika.westerberg@linux.intel.com Signed-off-by: Imre Deak imre.deak@intel.com Link: https://lore.kernel.org/r/20250519133417.1469181-1-imre.deak@intel.com (cherry picked from commit c3a48363cf1f76147088b1adb518136ac5df86a0) Signed-off-by: Joonas Lahtinen joonas.lahtinen@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/cpu/common.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 3390814de0a54..cc1bbf70477b0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2215,9 +2215,6 @@ EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
#endif /* CONFIG_X86_64 */
-/* - * Clear all 6 debug registers: - */ static void initialize_debug_regs(void) { /* Control register first -- to make sure everything is disabled. */