FreeBSD source tree https://cgit-dev.freebsd.org/src/atom?h=release%2F12.3.0 2020-10-22T17:31:41Z 2020-10-22T17:31:41Z Marcin Wojtas mw@FreeBSD.org 2020-10-22T17:31:41Z urn:sha1:028b7c704b7f429a834ca85daf7262ac782502d0 Fix AccessWidth and BitWidth parsing in SPCR table The ACPI Specification defines a Generic Address Structure (GAS), which is used to describe UART controller register layout in the SPCR table. The driver responsible for parsing it (uart_cpu_acpi) wrongly associates the Access Size field to the uart_bas's regshft and the register BitWidth to the regiowidth - according to the definitions it should be opposite. This problem remained hidden most likely because the majority of platforms use 32-bit registers (BitWidth) which are accessed with the according size (Dword). However on Marvell Armada 8k / Cn913x platforms, the 32-bit registers should be accessed with Byte granulity, which unveiled the issue. This patch fixes above by proper values assignment and slightly improved parsing. Note that handling of the AccessWidth set to EFI_ACPI_6_0_UNDEFINED is needed to work around a buggy SPCR table on EC2 x86 "bare metal" instances. Reviewed by: manu, imp, cperciva, greg_unrelenting.technology Obtained from: Semihalf 2019-05-28T22:22:40Z Colin Percival cperciva@FreeBSD.org 2019-05-28T22:22:40Z urn:sha1:92182fab8a21dc8f5356ffe82a6562b99b8a8516 r345405: Obey SPCR AccessWidth parameter. r345406: Initialize uart_bus_space_mem on arm64. r346228: Add quirk to ignore AccessWidth on PL011 UART. r346657: Handle SPCR BaudRate = 0. r348195: Extract arm64 SPCR code and make it MI; use on x86 too. r348198: Fix for r348195. This unbreaks the console on EC2 a1.* and *.metal instances. Sponsored by: https://www.patreon.com/cperciva