From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Thu, 27 Nov 2014 09:08:26 +0000 Subject: [PATCH 1/2] ARM: tegra: irq: fix buggy usage of irq_data irq field In-Reply-To: <20141127082836.GA19323@ulmo> References: <1417024532-5777-1-git-send-email-marc.zyngier@arm.com> <1417024532-5777-2-git-send-email-marc.zyngier@arm.com> <20141127082836.GA19323@ulmo> Message-ID: <5476EA0A.7090406@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Thierry, On 27/11/14 08:28, Thierry Reding wrote: > On Wed, Nov 26, 2014 at 05:55:31PM +0000, Marc Zyngier wrote: >> The crazy gic_arch_extn thing that Tegra uses contains multiple >> references to the irq field in struct irq_data, and uses this >> to directly poke hardware register. >> >> But irq is the *virtual* irq number, something that has nothing >> to do with the actual HW irq (stored in the hwirq field). And once >> we put the stacked domain code in action, the whole thing explodes, >> as these two values are *very* different: > > Do you have follow-up patches to use stacked domains on Tegra? I tried > to move this driver out to drivers/irqchip at some point and that caused > a bit of pain because of gic_arch_extn and probe order. At the time I > was told that work was in progress to provide a more generic solution > that could replace gic_arch_extn, which I'm assuming this stacked domain > code is. I'm working on that at the moment, and things look pretty good. The only issue I have so far is that this piece of HW needs to become the top-level interrupt-parent for all devices that are currently interrupting on the GIC. So far, the only solution I have is a change in the DT. But arguably, this should have been described in DT too... >> root at bacon-fat:~# cat /proc/interrupts >> CPU0 CPU1 >> 16: 25801 2075 GIC 29 twd >> 17: 0 0 GIC 73 timer0 >> 112: 0 0 GPIO 58 c8000600.sdhci cd >> 123: 0 0 GPIO 69 c8000200.sdhci cd >> 279: 1126 0 GIC 122 serial >> 281: 0 0 GIC 70 7000c000.i2c >> 282: 0 0 GIC 116 7000c400.i2c >> 283: 0 0 GIC 124 7000c500.i2c >> 284: 300 0 GIC 85 7000d000.i2c >> [...] >> >> Just replacing all instances of irq with hwirq fixes the issue. >> >> Signed-off-by: Marc Zyngier >> --- >> arch/arm/mach-tegra/irq.c | 22 +++++++++++----------- >> 1 file changed, 11 insertions(+), 11 deletions(-) > > This looks correct to me. Do you need this to base subsequent patches on > or shall I just take those through the Tegra tree? I'm not sure if the > ARM SoC maintainers will take a follow-up pull request for 3.19, so let > me know if there's a hurry to get this in if it's going to make stacked > domain code difficult to merge. Up to you, really. The only real issue is that when the stacked domain code hits mainline, Tegra will stop working without this patch. -next is probably already broken. I'd be tempted to consider it as a fix for 3.18, as the current code is obviously wrong. Just let me know how you want to get it in. Thanks, M. -- Jazz is not dead. It just smells funny...