From 9dcb3df4281876731e4e8bff7940514d72375154 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jonathan=20Neusch=C3=A4fer?= Date: Thu, 10 May 2018 23:59:19 +0200 Subject: [PATCH] powerpc/embedded6xx/hlwd-pic: Prevent interrupts from being handled by Starlet MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The interrupt controller inside the Wii's Hollywood chip is connected to two masters, the "Broadway" PowerPC and the "Starlet" ARM926, each with their own interrupt status and mask registers. When booting the Wii with mini[1], interrupts from the SD card controller (IRQ 7) are handled by the ARM, because mini provides SD access over IPC. Linux however can't currently use or disable this IPC service, so both sides try to handle IRQ 7 without coordination. Let's instead make sure that all interrupts that are unmasked on the PPC side are masked on the ARM side; this will also make sure that Linux can properly talk to the SD card controller (and potentially other devices). If access to a device through IPC is desired in the future, interrupts from that device should not be handled by Linux directly. [1]: https://github.com/lewurm/mini Signed-off-by: Jonathan Neuschäfer Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/embedded6xx/hlwd-pic.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c index 89c54de..bf4a125 100644 --- a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c +++ b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c @@ -35,6 +35,8 @@ */ #define HW_BROADWAY_ICR 0x00 #define HW_BROADWAY_IMR 0x04 +#define HW_STARLET_ICR 0x08 +#define HW_STARLET_IMR 0x0c /* @@ -74,6 +76,9 @@ static void hlwd_pic_unmask(struct irq_data *d) void __iomem *io_base = irq_data_get_irq_chip_data(d); setbits32(io_base + HW_BROADWAY_IMR, 1 << irq); + + /* Make sure the ARM (aka. Starlet) doesn't handle this interrupt. */ + clrbits32(io_base + HW_STARLET_IMR, 1 << irq); } -- 2.7.4