From: Linus Torvalds Date: Wed, 23 Dec 2009 23:04:53 +0000 (-0800) Subject: Revert "x86, ucode-amd: Ensure ucode update on suspend/resume after CPU off/online... X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2f99f5c8f05e02f3df1bb4d93b6704e6f5972872;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git Revert "x86, ucode-amd: Ensure ucode update on suspend/resume after CPU off/online cycle" This reverts commit 9f15226e75583547aaf542c6be4bdac1060dd425. It's just wrong, and broke resume for Rafael even on a non-AMD CPU. As Rafael says: "... it causes microcode_init_cpu() to be called during resume even for CPUs for which there's no microcode to apply. That, in turn, results in executing request_firmware() (on Intel CPUs at least) which doesn't work at this stage of resume (we have device interrupts disabled, I/O devices are still suspended and so on). If I'm not mistaken, the "if (uci->valid)" logic means "if that CPU is known to us" , so before commit 9f15226e755 microcode_resume_cpu() was called for all CPUs already in the system during suspend, which was the right thing to do. The commit changed it so that the CPUs without microcode to apply are now treated as "unknown", which is not quite right. The problem this commit attempted to solve has to be handled differently." Bisected-and -requested-by: Rafael J. Wysocki Signed-off-by: Linus Torvalds --- diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c index 844c02c65fc..0c863243309 100644 --- a/arch/x86/kernel/microcode_core.c +++ b/arch/x86/kernel/microcode_core.c @@ -394,7 +394,7 @@ static enum ucode_state microcode_update_cpu(int cpu) struct ucode_cpu_info *uci = ucode_cpu_info + cpu; enum ucode_state ustate; - if (uci->valid && uci->mc) + if (uci->valid) ustate = microcode_resume_cpu(cpu); else ustate = microcode_init_cpu(cpu);