drivers/irqchip/irq-ti-sci-intr.c:148 ti_sci_intr_alloc_parent_irq() warn: impossible condition '(p_hwirq < 0) => (0-u16max < 0)'

From: Dan Carpenter
Date: Thu Sep 03 2020 - 08:55:54 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: fc3abb53250a90ba2150eebd182137c136f4d25a
commit: a5b659bd4bc7518a8e45fda5256c5e5e8d3b7c49 irqchip/ti-sci-intr: Add support for INTR being a parent to INTR
config: arm64-randconfig-m031-20200902 (attached as .config)
compiler: aarch64-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

smatch warnings:
drivers/irqchip/irq-ti-sci-intr.c:148 ti_sci_intr_alloc_parent_irq() warn: impossible condition '(p_hwirq < 0) => (0-u16max < 0)'

# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a5b659bd4bc7518a8e45fda5256c5e5e8d3b7c49
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout a5b659bd4bc7518a8e45fda5256c5e5e8d3b7c49
vim +148 drivers/irqchip/irq-ti-sci-intr.c

a5b659bd4bc751 Lokesh Vutla 2020-08-06 134 static int ti_sci_intr_alloc_parent_irq(struct irq_domain *domain,
cd844b0715ceda Lokesh Vutla 2019-04-30 135 unsigned int virq, u32 hwirq)
cd844b0715ceda Lokesh Vutla 2019-04-30 136 {
cd844b0715ceda Lokesh Vutla 2019-04-30 137 struct ti_sci_intr_irq_domain *intr = domain->host_data;
a5b659bd4bc751 Lokesh Vutla 2020-08-06 138 struct device_node *parent_node;
cd844b0715ceda Lokesh Vutla 2019-04-30 139 struct irq_fwspec fwspec;
a5b659bd4bc751 Lokesh Vutla 2020-08-06 140 u16 out_irq, p_hwirq;
^^^ ^^^^^^^

a5b659bd4bc751 Lokesh Vutla 2020-08-06 141 int err = 0;
cd844b0715ceda Lokesh Vutla 2019-04-30 142
a5b659bd4bc751 Lokesh Vutla 2020-08-06 143 out_irq = ti_sci_get_free_resource(intr->out_irqs);
a5b659bd4bc751 Lokesh Vutla 2020-08-06 144 if (out_irq == TI_SCI_RESOURCE_NULL)
cd844b0715ceda Lokesh Vutla 2019-04-30 145 return -EINVAL;
cd844b0715ceda Lokesh Vutla 2019-04-30 146
a5b659bd4bc751 Lokesh Vutla 2020-08-06 147 p_hwirq = ti_sci_intr_xlate_irq(intr, out_irq);
a5b659bd4bc751 Lokesh Vutla 2020-08-06 @148 if (p_hwirq < 0)
^^^^^^^^^^^
Impossible

a5b659bd4bc751 Lokesh Vutla 2020-08-06 149 goto err_irqs;
a5b659bd4bc751 Lokesh Vutla 2020-08-06 150
a5b659bd4bc751 Lokesh Vutla 2020-08-06 151 parent_node = of_irq_find_parent(dev_of_node(intr->dev));
a5b659bd4bc751 Lokesh Vutla 2020-08-06 152 fwspec.fwnode = of_node_to_fwnode(parent_node);
a5b659bd4bc751 Lokesh Vutla 2020-08-06 153
a5b659bd4bc751 Lokesh Vutla 2020-08-06 154 if (of_device_is_compatible(parent_node, "arm,gic-v3")) {
a5b659bd4bc751 Lokesh Vutla 2020-08-06 155 /* Parent is GIC */
cd844b0715ceda Lokesh Vutla 2019-04-30 156 fwspec.param_count = 3;
cd844b0715ceda Lokesh Vutla 2019-04-30 157 fwspec.param[0] = 0; /* SPI */
a5b659bd4bc751 Lokesh Vutla 2020-08-06 158 fwspec.param[1] = p_hwirq - 32; /* SPI offset */
cd844b0715ceda Lokesh Vutla 2019-04-30 159 fwspec.param[2] = intr->type;
a5b659bd4bc751 Lokesh Vutla 2020-08-06 160 } else {
a5b659bd4bc751 Lokesh Vutla 2020-08-06 161 /* Parent is Interrupt Router */
a5b659bd4bc751 Lokesh Vutla 2020-08-06 162 fwspec.param_count = 1;
a5b659bd4bc751 Lokesh Vutla 2020-08-06 163 fwspec.param[0] = p_hwirq;
a5b659bd4bc751 Lokesh Vutla 2020-08-06 164 }
cd844b0715ceda Lokesh Vutla 2019-04-30 165
cd844b0715ceda Lokesh Vutla 2019-04-30 166 err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
cd844b0715ceda Lokesh Vutla 2019-04-30 167 if (err)
cd844b0715ceda Lokesh Vutla 2019-04-30 168 goto err_irqs;
cd844b0715ceda Lokesh Vutla 2019-04-30 169
a5b659bd4bc751 Lokesh Vutla 2020-08-06 170 err = intr->sci->ops.rm_irq_ops.set_irq(intr->sci,
a5b659bd4bc751 Lokesh Vutla 2020-08-06 171 intr->ti_sci_id, hwirq,
a5b659bd4bc751 Lokesh Vutla 2020-08-06 172 intr->ti_sci_id, out_irq);
cd844b0715ceda Lokesh Vutla 2019-04-30 173 if (err)
cd844b0715ceda Lokesh Vutla 2019-04-30 174 goto err_msg;
cd844b0715ceda Lokesh Vutla 2019-04-30 175
a5b659bd4bc751 Lokesh Vutla 2020-08-06 176 return p_hwirq;
cd844b0715ceda Lokesh Vutla 2019-04-30 177
cd844b0715ceda Lokesh Vutla 2019-04-30 178 err_msg:
cd844b0715ceda Lokesh Vutla 2019-04-30 179 irq_domain_free_irqs_parent(domain, virq, 1);
cd844b0715ceda Lokesh Vutla 2019-04-30 180 err_irqs:
a5b659bd4bc751 Lokesh Vutla 2020-08-06 181 ti_sci_release_resource(intr->out_irqs, out_irq);
cd844b0715ceda Lokesh Vutla 2019-04-30 182 return err;
cd844b0715ceda Lokesh Vutla 2019-04-30 183 }

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Attachment: .config.gz
Description: application/gzip