Messages in this thread | | | Date | Fri, 25 Feb 2011 10:54:28 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH v5 1/2] PRUSS UIO driver support |
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On Fri, 25 Feb 2011, Pratheesh Gangadhar wrote: > +static irqreturn_t pruss_handler(int irq, struct uio_info *dev_info) > +{ > + void __iomem *base = dev_info->mem[0].internal_addr; > + void __iomem *intren_reg = base + PINTC_HIER; > + void __iomem *intrstat_reg = base + PINTC_HIPIR + ((irq - 1) << 2); > + int val = ioread32(intren_reg), intr_mask = (1 << (irq - 1)); > + > + /* Is interrupt enabled and active ? */ > + if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND)) > + return IRQ_NONE; > + > + /* Disable interrupt */ > + iowrite32((val & ~intr_mask), intren_reg); > + return IRQ_HANDLED; > +}
Hmm, just noticed, that you fiddle with the interrupt enable register here totally unprotected. So on a SMP system you might haandle two different interrupts at the same time. That wants locking.
And even on UP, you have a problem as you reenable that thing from user space which requires a read modify write. Racy as hell.
Please look at the other UIO drivers which have the same problem. Sorry for not noticing earlier!
Thanks,
tglx
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