Date: Sun, 19 May 2019 05:44:43 +0000 From: bugzilla-noreply@freebsd.org To: acpi@FreeBSD.org Subject: [Bug 231760] FreeBSD 12.0-ALPHA7 Installations Halts at ACPI on 4 different AMD Ryzen Laptops (HP, DELL, Huawei) Message-ID: <bug-231760-16045-mJTLklarnO@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-231760-16045@https.bugs.freebsd.org/bugzilla/> References: <bug-231760-16045@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D231760 John Baldwin <jhb@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |markj@FreeBSD.org --- Comment #16 from John Baldwin <jhb@FreeBSD.org> --- I got access to two laptops at BSDCan tonight and figured out the bug. I'll clean up the patch I came up with and post it soonish. However, the short version is that the _PIC method in ACPI called a function that directly accessed PCI config registers via the MCFG mapping to clear a bit when enab= ling APIC mode. However, since the BIOS didn't use PCI config space but directly accessed MCFG directly via SystemMemory, AcpiOsMapMemory was used to map MC= FG.=20 This called pmap_mapbios() which remapped the MCFG window as Write-Back ins= tead of UC and the laptops hung right after this. The fix is to add yet another variant of pmap_mapdev() which leaves the existing PAT mode alone and doesn= 't change it and change AcpiOsMapMemory to use that instead of pmap_mapbios. --=20 You are receiving this mail because: You are on the CC list for the bug.=
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