From mboxrd@z Thu Jan 1 00:00:00 1970 From: majun258@huawei.com (majun (F)) Date: Mon, 27 Jul 2015 10:25:05 +0800 Subject: [PATCH v3 1/3] IRQ/Gic-V3: Add mbigen driver to support mbigen interrupt controller In-Reply-To: <55A7B3A5.6010008@arm.com> References: <1436166548-34920-1-git-send-email-majun258@huawei.com> <1436166548-34920-2-git-send-email-majun258@huawei.com> <559CA530.2090508@huawei.com> <559D3EB5.4060408@arm.com> <55A76CBE.2030508@huawei.com> <55A770E2.2040300@arm.com> <55A777BD.4080504@huawei.com> <55A77999.9000203@arm.com> <55A7A2F9.3000306@huawei.com> <55A7B3A5.6010008@arm.com> Message-ID: <55B59681.2090008@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Marc ? 2015/7/16 21:37, Marc Zyngier ??: [...] >> >> For example, An device with total 5 interrupts connected to Mbigen node. >> In mbigen chip, the default eventID value for each device starts from 0. >> So, for these 5 interrupts the default eventID value is from 0 to 4. >> >> Because the default eventID is fixed in mbigen chip, to make these 5 interrupt >> work, the only way is define all these 5 interrupts in dts file. > > But the ITS doesn't read these interrupts, and won't let you program the > translation either. > >> When irq initializing, ITS driver will allocat LPI interrupt number for these >> 5 interrupts, for example : from 8192 to 8196. and the eventID value is from 0 to 4. >> Now, the allocated eventID value same as the eventID value encoded in mbigen chip, >> The interrupt can work. > > But that's pure luck! What if I decide to change the allocation method > so that all the devices share a common ITT? > > Have you really hardcoded the Linux behaviour in your hardware? > >> I know this is not a good method,but for current mbigen chip,it's the only solution. > > I'm sorry, I can't call this a solution. Yes,you are right. This is not a right way to solve the problem. This problem will be fixed in next version chip. > > M. >