From 2f3736e7aceb289d51a54679747d65eb09c1e0f1 Mon Sep 17 00:00:00 2001 From: Duncan Laurie Date: Thu, 3 Nov 2016 10:33:43 -0700 Subject: soc/intel/{sky,apollo}lake: Wait until GPE is clear when reading When reading+clearing a GPE for use as an interrupt we need to re-read the status register and keep setting the clear bit until it actually reads back clear. Also add a 1ms timeout in case the status never clears. This is needed if a device sends a longer interrupt pulse and it is still asserted when the "ISR" goes to clear the status. BUG=chrome-os-partner:59299 TEST=test cr50 TPM with 20us pulse to ensure it can successfully communicate with the TPM and does not get confused due to seeing interrupts that it should not. Change-Id: I384f484a1728038d3a355586146deee089b22dd9 Signed-off-by: Duncan Laurie Reviewed-on: https://review.coreboot.org/17212 Tested-by: build bot (Jenkins) Reviewed-by: Furquan Shaikh Reviewed-by: Paul Menzel --- src/soc/intel/skylake/pmutil.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) (limited to 'src/soc/intel/skylake') diff --git a/src/soc/intel/skylake/pmutil.c b/src/soc/intel/skylake/pmutil.c index 203a430ffa..73dc11792c 100644 --- a/src/soc/intel/skylake/pmutil.c +++ b/src/soc/intel/skylake/pmutil.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "chip.h" /* Print status bits with descriptive names */ @@ -361,6 +362,8 @@ int acpi_get_gpe(int gpe) { int bank; uint32_t mask, sts; + struct stopwatch sw; + int rc = 0; if (gpe < 0 || gpe > GPE0_WADT) return -1; @@ -368,12 +371,20 @@ int acpi_get_gpe(int gpe) bank = gpe / 32; mask = 1 << (gpe % 32); - sts = inl(ACPI_BASE_ADDRESS + GPE0_STS(bank)); - if (sts & mask) { - outl(mask, ACPI_BASE_ADDRESS + GPE0_STS(bank)); - return 1; - } - return 0; + /* Wait up to 1ms for GPE status to clear */ + stopwatch_init_msecs_expire(&sw, 1); + do { + if (stopwatch_expired(&sw)) + return rc; + + sts = inl(ACPI_BASE_ADDRESS + GPE0_STS(bank)); + if (sts & mask) { + outl(mask, ACPI_BASE_ADDRESS + GPE0_STS(bank)); + rc = 1; + } + } while (sts & mask); + + return rc; } /* Enable all requested GPE */ -- cgit v1.2.3