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[Qemu-devel] [PULL 6/8] bcm2835_aux: Swap RX and TX interrupt assignment
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PULL 6/8] bcm2835_aux: Swap RX and TX interrupt assignments |
Date: |
Mon, 16 Jul 2018 17:42:58 +0100 |
From: Guenter Roeck <address@hidden>
RX and TX interrupt bits were reversed, resulting in an endless sequence
of serial interupts in the emulated system and the following repeated
error message when booting Linux.
serial8250: too much work for irq61
This results in a boot failure most of the time.
Qemu command line used to reproduce the problem:
qemu-system-aarch64 -M raspi3 -m 1024 \
-kernel arch/arm64/boot/Image \
--append "rdinit=/sbin/init console=ttyS1,115200"
-initrd rootfs.cpio \
-dtb arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dtb \
-nographic -monitor null -serial null -serial stdio
This is with arm64:defconfig. The root file system was generated using
buildroot.
NB that this error likely arises from an erratum in the
BCM2835 datasheet where the TX and RX bits were swapped
in the AU_MU_IER_REG description (but correct for IIR):
https://elinux.org/BCM2835_datasheet_errata#p12
Signed-off-by: Guenter Roeck <address@hidden>
Message-id: address@hidden
Reviewed-by: Peter Maydell <address@hidden>
[PMM: added NB about datasheet]
Signed-off-by: Peter Maydell <address@hidden>
---
hw/char/bcm2835_aux.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/hw/char/bcm2835_aux.c b/hw/char/bcm2835_aux.c
index 370dc7e2968..0364596c552 100644
--- a/hw/char/bcm2835_aux.c
+++ b/hw/char/bcm2835_aux.c
@@ -39,8 +39,8 @@
#define AUX_MU_BAUD_REG 0x68
/* bits in IER/IIR registers */
-#define TX_INT 0x1
-#define RX_INT 0x2
+#define RX_INT 0x1
+#define TX_INT 0x2
static void bcm2835_aux_update(BCM2835AuxState *s)
{
--
2.17.1
- [Qemu-devel] [PULL 0/8] target-arm queue, Peter Maydell, 2018/07/16
- [Qemu-devel] [PULL 3/8] hw/intc/arm_gic: Check interrupt number in gic_deactivate_irq(), Peter Maydell, 2018/07/16
- [Qemu-devel] [PULL 4/8] hw/intc/arm_gic: Fix handling of GICD_ITARGETSR, Peter Maydell, 2018/07/16
- [Qemu-devel] [PULL 2/8] aspeed: Implement write-1-{set, clear} for AST2500 strapping, Peter Maydell, 2018/07/16
- [Qemu-devel] [PULL 1/8] target/arm: Fix LD1W and LDFF1W (scalar plus vector), Peter Maydell, 2018/07/16
- [Qemu-devel] [PULL 5/8] hw/arm/bcm2836: Mark the bcm2836 / bcm2837 devices with user_creatable = false, Peter Maydell, 2018/07/16
- [Qemu-devel] [PULL 8/8] accel/tcg: Assert that tlb fill gave us a valid TLB entry, Peter Maydell, 2018/07/16
- [Qemu-devel] [PULL 6/8] bcm2835_aux: Swap RX and TX interrupt assignments,
Peter Maydell <=
- [Qemu-devel] [PULL 7/8] accel/tcg: Use correct test when looking in victim TLB for code, Peter Maydell, 2018/07/16
- Re: [Qemu-devel] [PULL 0/8] target-arm queue, Peter Maydell, 2018/07/17