> -----Original Message----- > From: Siddha, Suresh B > Sent: Tuesday, October 30, 2012 4:24 AM > To: Liu, Chuansheng > Cc: mi...@redhat.com; h...@zytor.com; t...@linutronix.de; > ying...@kernel.org; x...@kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] x86/ioapic: Fix the vector_irq[] is corrupted randomly > > On Tue, 2012-10-30 at 00:15 +0800, Chuansheng Liu wrote: > > Not all irq chips are IO-APIC chip. > > > > In our system, there are many demux GPIO interrupts except for the > > io-apic chip interrupts, and these GPIO interrupts are belonged > > to other irq chips, the chip data is not type of struct irq_cfg > > either. > > > > But in function __setup_vector_irq(), it listed all allocated irqs, > > and presume all irq chip is ioapic_chip and the chip data is type > > of struct irq_cfg, it possibly causes the vector_irq is corrupted > > randomly. > > > > For example, one irq 258 is not io-apic chip irq, in __setup_vector_irq(), > > the chip data is forced to be used as struct irq_cfg, then the value > > cfg->domain and cfg->vector are wrong to be used to write vector_irq: > > vector = cfg->vector; > > per_cpu(vector_irq, cpu)[vector] = irq; > > > > This patch use the .flags to identify if the irq chip is io-apic. > > I have a feeling that your gpio driver is abusing the 'chip_data' in the > struct irq_data. Shouldn't the driver be using 'handler_data' instead? Not abusing.
There are many driver codes which has their own chip and chip_data. For example, langwell_gpio.c, the chip_data type is struct lnw_gpio; gpio_omap.c, the chip_data type is struct gpio_bank; In these cases, if we abused the gpio chip_data type with struct irq_cfg, we will get very wrong cfg->vector, the value maybe 1 or 1000, anyway, it is a random value. > > From include/linux/irq.h: > * @handler_data: per-IRQ data for the irq_chip methods > * @chip_data: platform-specific per-chip private data for the chip > * methods, to allow shared chip implementations > > Also, how are these routed to the processors and the mechanism of the > vector assignment for these irq's? I presume irq_cfg is needed for the > setup and the interrupt migration from one cpu to another. Normally gpio chip just has only one base irq is related with io-apic interrupt, other allocated *VIRTUAL* irqs are based on this base irq, so no vector assign to them. But in code __setup_vector_irq(), it list all allocated irqs which include the *VIRTUAL* irqs, It causes this case that chip_data type is abused. > > What am I missing? > > thanks, > suresh