d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

uart_dev_ns8250: Switch ACPI UART subtype for Marvell SoCs

Browse Source 
DBG2 ACPI table description [1] specifies three subtypes
related to 16550 UART:
0x0 - 16550 compatible
0x1 - 16550 subset
0x12 - 16550 compatible with parameters defined in Generic Address Structure (GAS)

It turned out however, that the Windows OS treats 0x0 subtype as
legacy x86 UART with 8-bit access. ARM SoCs can use types 0x1 (16550 with
fixed mmio32 access) or 0x12 (16550 with fully respected GAS contents).

Switch Marvell SoCs ACPI UART subtype to 0x1 - thanks to that the same firmware
can run properly with UART output in FreeBSD, Windows 10, Linux and ESXI
hypervisor. Tests showed the older firmware versions that use 0x0
UART subtype in SPCR table continue to display output properly.

[1] https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/acpi-debug-port-table

Obtained from: Semihalf
Sponsored by: ARM
Differential revision: https://reviews.freebsd.org/D30386
MFC after: 2 weeks
This commit is contained in:
Marcin Wojtas 2021-05-20 23:37:02 +02:00
parent 847b7d5054
commit 9cf66a0458
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sys/dev/uart/uart_dev_ns8250.c
View File

@ -57,6 +57,7 @@ __FBSDID("$FreeBSD$");
#include <dev/uart/uart_ppstypes.h>
#ifdef DEV_ACPI
#include <dev/uart/uart_cpu_acpi.h>
#include <contrib/dev/acpica/include/acpi.h>
#endif
#include <dev/ic/ns16550.h>
@ -415,7 +416,7 @@ struct uart_class uart_ns8250_class = {
static struct acpi_uart_compat_data acpi_compat_data[] = {
{"AMD0020", &uart_ns8250_class, 0, 2, 0, 48000000, UART_F_BUSY_DETECT, "AMD / Synopsys Designware UART"},
{"AMDI0020", &uart_ns8250_class, 0, 2, 0, 48000000, UART_F_BUSY_DETECT, "AMD / Synopsys Designware UART"},
{"MRVL0001", &uart_ns8250_class, 0, 2, 0, 200000000, UART_F_BUSY_DETECT, "Marvell / Synopsys Designware UART"},
{"MRVL0001", &uart_ns8250_class, ACPI_DBG2_16550_SUBSET, 2, 0, 200000000, UART_F_BUSY_DETECT, "Marvell / Synopsys Designware UART"},
{"SCX0006", &uart_ns8250_class, 0, 2, 0, 62500000, UART_F_BUSY_DETECT, "SynQuacer / Synopsys Designware UART"},
{"HISI0031", &uart_ns8250_class, 0, 2, 0, 200000000, UART_F_BUSY_DETECT, "HiSilicon / Synopsys Designware UART"},
{"PNP0500", &uart_ns8250_class, 0, 0, 0, 0, 0, "Standard PC COM port"},