Messages in this thread | | | Subject | Re: [PATCH] mbigen: don't clear eventid when free_irq | From | Chen Jianguo <> | Date | Thu, 21 Mar 2019 21:21:40 +0800 |
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Hi Marc On 2019/3/21 17:11, Marc Zyngier wrote: > On Sat, 16 Mar 2019 11:15:03 +0000 > chenjianguo <chenjianguo3@huawei.com> wrote: > >> From: Jianguo Chen <chenjianguo3@huawei.com> >> >> mbigen_write_msg clears eventid bits of a mbigen register >> when free a interrupt, because msi_domain_deactivate memset >> struct msg to zero. Then multiple mbigen pins with zero eventid >> will report the same interrupt number. >> >> The eventid clear call trace: >> free_irq >> __free_irq >> irq_shutdown >> irq_domain_deactivate_irq >> __irq_domain_deactivate_irq >> __irq_domain_deactivate_irq >> msi_domain_deactivate >> platform_msi_write_msg >> mbigen_write_msg >> >> Signed-off-by: Jianguo Chen <chenjianguo3@huawei.com> >> --- >> drivers/irqchip/irq-mbigen.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c >> index 567b29c..fad7291 100644 >> --- a/drivers/irqchip/irq-mbigen.c >> +++ b/drivers/irqchip/irq-mbigen.c >> @@ -161,6 +161,9 @@ static void mbigen_write_msg(struct msi_desc *desc, >> struct msi_msg *msg) >> void __iomem *base = d->chip_data; >> u32 val; >> >> + if (!msg->address_lo && !msg->address_hi) >> + return; >> + >> base += get_mbigen_vec_reg(d->hwirq); >> val = readl_relaxed(base); >> > > For whatever reason, I couldn't apply this patch (even when fishing a > copy of this email from the archives). It seems to be corrupted is > various ways, so I had to write the patch from scratch, which is not the > most reliable way to work. Good thing this was something trivial, I > wouldn't do it for something more complicated. > > In the future, please make sure to use 'git send-email' to send your > patches, as it is known to work correctly. > > Thanks, > > M. >
Mbigen vector register and pin structure shows as below:
event id 0 1 2 127 vector register reg0 reg1 reg2 reg127 | | | | MBIGEN pin0 pin1 pin2 ... pin127 |-----|-----|-----|-----| | | | | | device interrupt num0 num1 num2 num127
Suppose a device driver requested irq num0 and num1 at the beginning, and for some reason it freed irq num1, mbigen_write_msg will write reg1 with event id 0. Then the pin1 probably mistakenly report interrupt num0 to device driver if there is a signal on the pin.
event id 0 0 2 127 vector register reg0 reg1 reg2 reg127 | | | | MBIGEN pin0 pin1 pin2 ... pin127 |-----|-----|-----|-----| | | | | | device interrup num0 num1 num2 num127
Thanks, Jianguo Chen
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