git: a74df3f96e3e - main - iicbb: Fix pause_sbt() arguments order
- Go to: [ bottom of page ] [ top of archives ] [ this month ]
Date: Sat, 23 Dec 2023 23:59:17 UTC
The branch main has been updated by mav: URL: https://cgit.FreeBSD.org/src/commit/?id=a74df3f96e3ea4cc632088be870d9b0b0198859c commit a74df3f96e3ea4cc632088be870d9b0b0198859c Author: Alexander Motin <mav@FreeBSD.org> AuthorDate: 2023-12-23 23:52:17 +0000 Commit: Alexander Motin <mav@FreeBSD.org> CommitDate: 2023-12-23 23:58:51 +0000 iicbb: Fix pause_sbt() arguments order It should make pause interval less strict. While there, add cpu_spinwait() into a tight spin wait loop to burn less power and let other SMT thread work more. MFC after: 1 month --- sys/dev/iicbus/iicbb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/sys/dev/iicbus/iicbb.c b/sys/dev/iicbus/iicbb.c index 3948d5d5a9f6..5d6ac48d4543 100644 --- a/sys/dev/iicbus/iicbb.c +++ b/sys/dev/iicbus/iicbb.c @@ -52,6 +52,7 @@ #include <sys/bus.h> #include <sys/sysctl.h> #include <sys/uio.h> +#include <machine/cpu.h> #ifdef FDT #include <dev/ofw/ofw_bus.h> @@ -254,11 +255,12 @@ iicbb_waitforscl(device_t dev) do { if (I2C_GETSCL(dev)) return (0); + cpu_spinwait(); now = sbinuptime(); } while (now < fast_timeout); do { I2C_DEBUG(printf(".")); - pause_sbt("iicbb-scl-low", SBT_1MS, C_PREL(8), 0); + pause_sbt("iicbb-scl-low", SBT_1MS, 0, C_PREL(2)); if (I2C_GETSCL(dev)) return (0); now = sbinuptime();