On 7 October 2011 05:26, Thomas Abraham <thomas.abraham@xxxxxxxxxx> wrote: > Hi Russell, > > On 7 October 2011 03:45, Russell King - ARM Linux > <linux@xxxxxxxxxxxxxxxx> wrote: >> On Fri, Oct 07, 2011 at 02:41:42AM +0530, Thomas Abraham wrote: >>> All of Samsung's s5p platforms have timer irqs statically mapped from linux >>> irq numbers 11 to 15. These timer irqs are moved to end of the statically >>> mapped linux irq space and the hardware irqs, which were statically mapped >>> starting from 32 is moved to start from 0. The NR_IRQS macro is consolidated >>> for all the s5p platforms in this process. >> >> Am I reading this patch correctly - in that on platforms with the GIC, >> you add 32 to the GIC IRQ number _just_ to avoid the possibility that >> IRQs 11-15 are seen as valid? >> >> Or to put it another way, you're trying to ensure that if these timer >> IRQs are requested, they will fail? >> > > This patch is applicable for s5p64x0, s5pc100, s5pv210 and exynos4. > Exynos4 has GIC and the rest use VIC. > > For all these platforms, the five hardware timer irqs are connected to > GIC/VIC at some hardware irq number (in exynos it is GIC_ID 69 to 73 > for five timers). When any of these hardware interrupt occurs, its > interrupt handler calls generic_handle_irq() with linux irq number > 11/12/13/14/15 for timer 0/1/2/3/4 as the parameter. The code that > needs to be notified about the timer interrupts would have already > registered its handler for either of the interrupts 11 to 15. I am not > sure why such remapping is used. I think it is not needed but did not > intend to change it. All this is included in the file > "arch/arm/plat-samsung/irq-vic-timer.c". > > Instead of using linux irq number 11 to 15 to which consumers of timer > interrupt attach their handler, this interrupt range is moved to the > end of linux irq space used. So there will be no interrupts statically > mapped between 0 to 31. > > The GIC/VIC hardware interrupts, which were previously statically > mapped to start from linux irq 32 are now moved to start from linux > irq 0. In case of exynos, GIC_ID[0] (which is SGI[0]) which was > previously at linux irq 32, will not be at linux irq 0. Correcting the line above: previously at linux irq 32, will _now_ be at linux irq 0. > > This was the intended change. This was required to use Rob Herring's > GIC OF bindings patches for Exynos4. > > Thanks, > Thomas. > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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