On Tue, Oct 26, 2021 at 03:28:29PM +0800, Shuai Xue wrote: > When injecting an error into the platform, the OSPM executes an > EXECUTE_OPERATION action to instruct the platform to begin the injection > operation. And then, the OSPM busy waits for a while by continually > executing CHECK_BUSY_STATUS action until the platform indicates that the > operation is complete. More specifically, the platform is limited to > respond within 1 millisecond right now. This is too strict for some > platforms. > > For example, in Arm platform, when injecting a Processor Correctable error, > the OSPM will warn: > Firmware does not respond in time. > > And a message is printed on the console: > echo: write error: Input/output error > > We observe that the waiting time for DDR error injection is about 10 ms and > that for PCIe error injection is about 500 ms in Arm platform. > > In this patch, we relax the response timeout to 1 second. > > Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> Rafael: Do you want to take this in the acpi tree? If not, I can apply it to the RAS tree (already at -rc7, so in next merge cycle after 5.16-rc1 comes out). > --- > Changelog v2 -> v3: > - Implemented the timeout in usleep_range instead of msleep. > - Dropped command line interface of timeout. > - Link to the v1 patch: https://lkml.org/lkml/2021/10/14/1402 > --- > drivers/acpi/apei/einj.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c > index 133156759551..6e1ff4b62a8f 100644 > --- a/drivers/acpi/apei/einj.c > +++ b/drivers/acpi/apei/einj.c > @@ -28,9 +28,10 @@ > #undef pr_fmt > #define pr_fmt(fmt) "EINJ: " fmt > > -#define SPIN_UNIT 100 /* 100ns */ > -/* Firmware should respond within 1 milliseconds */ > -#define FIRMWARE_TIMEOUT (1 * NSEC_PER_MSEC) > +#define SLEEP_UNIT_MIN 1000 /* 1ms */ > +#define SLEEP_UNIT_MAX 5000 /* 5ms */ > +/* Firmware should respond within 1 seconds */ > +#define FIRMWARE_TIMEOUT (1 * USEC_PER_SEC) > #define ACPI5_VENDOR_BIT BIT(31) > #define MEM_ERROR_MASK (ACPI_EINJ_MEMORY_CORRECTABLE | \ > ACPI_EINJ_MEMORY_UNCORRECTABLE | \ > @@ -171,13 +172,13 @@ static int einj_get_available_error_type(u32 *type) > > static int einj_timedout(u64 *t) > { > - if ((s64)*t < SPIN_UNIT) { > + if ((s64)*t < SLEEP_UNIT_MIN) { > pr_warn(FW_WARN "Firmware does not respond in time\n"); > return 1; > } > - *t -= SPIN_UNIT; > - ndelay(SPIN_UNIT); > - touch_nmi_watchdog(); > + *t -= SLEEP_UNIT_MIN; > + usleep_range(SLEEP_UNIT_MIN, SLEEP_UNIT_MAX); > + > return 0; > } > > -- > 2.20.1.12.g72788fdb >
