fsp_Broadwell_DE: Do not set IRQ3 and IRQ4 to level

When booting Linux as a coreboot payload, serial access does not work
properly. This is because the setup code erroneously sets IRQ3 and
IRQ4 to level. The UART on Broadwell is 8250/16550 compatible, thus
ISA and edge-triggered.

This change is not necessary on the non-FSP version of Broadwell support.
The non-FSP version does not set these IRQ overrides.

Fix verified booting Linux 4.6.0-rc2 on Intel Camelback Mountain CRB,
using Intel FSP 1.0.

Change-Id: I17b466676e7f4891c3e75ce6208e1580c9eaf742
Signed-off-by: Kevin Paul Herbert <kevin@trippers.org>
Reviewed-on: https://review.coreboot.org/16065
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

1 files changed, 0 insertions, 10 deletions

diff --git a/src/soc/intel/fsp_broadwell_de/acpi.c b/src/soc/intel/fsp_broadwell_de/acpi.c
index 1647505820..4c6417d5d8 100644
--- a/src/soc/intel/fsp_broadwell_de/acpi.c
+++ b/src/soc/intel/fsp_broadwell_de/acpi.c
@@ -567,15 +567,5 @@ unsigned long acpi_madt_irq_overrides(unsigned long current)
 	current += acpi_create_madt_irqoverride(irqovr, 0, sci_irq, sci_irq,
 	                                        sci_flags);
 
-	irqovr = (void *)current;
-	current += acpi_create_madt_irqoverride(irqovr, 0, 3, 3,
-	                                       (MP_IRQ_TRIGGER_LEVEL
-	                                       |MP_IRQ_POLARITY_LOW));
-
-	irqovr = (void *)current;
-	current += acpi_create_madt_irqoverride(irqovr, 0, 4, 4,
-	                                       (MP_IRQ_TRIGGER_LEVEL
-	                                       |MP_IRQ_POLARITY_LOW));
-
 	return current;
 }