[PATCH 1/2] spi: fsl: don't map irq during probe

From: Christophe Leroy
Date: Mon Dec 09 2019 - 10:27:32 EST


With lastest kernel, the following warning is observed at startup:

[ 1.500609] ------------[ cut here ]------------
[ 1.505225] remove_proc_entry: removing non-empty directory 'irq/22', leaking at least 'fsl_spi'
[ 1.514234] WARNING: CPU: 0 PID: 1 at fs/proc/generic.c:682 remove_proc_entry+0x198/0x1c0
[ 1.522403] CPU: 0 PID: 1 Comm: swapper Not tainted 5.4.0-s3k-dev-02248-g93532430a4ff #2564
[ 1.530724] NIP: c0197694 LR: c0197694 CTR: c0050d80
[ 1.535762] REGS: df4a5af0 TRAP: 0700 Not tainted (5.4.0-02248-g93532430a4ff)
[ 1.543818] MSR: 00029032 <EE,ME,IR,DR,RI> CR: 22028222 XER: 00000000
[ 1.550524]
[ 1.550524] GPR00: c0197694 df4a5ba8 df4a0000 00000054 00000000 00000000 00004a38 00000010
[ 1.550524] GPR08: c07c5a30 00000800 00000000 00001032 22000208 00000000 c0004b14 00000000
[ 1.550524] GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 c0830000 c07fc078
[ 1.550524] GPR24: c08e8ca0 df665d10 df60ea98 c07c9db8 00000001 df5d5ae3 df5d5a80 df43f8e3
[ 1.585327] NIP [c0197694] remove_proc_entry+0x198/0x1c0
[ 1.590628] LR [c0197694] remove_proc_entry+0x198/0x1c0
[ 1.595829] Call Trace:
[ 1.598280] [df4a5ba8] [c0197694] remove_proc_entry+0x198/0x1c0 (unreliable)
[ 1.605321] [df4a5bd8] [c0067acc] unregister_irq_proc+0x5c/0x70
[ 1.611238] [df4a5bf8] [c005fbc4] free_desc+0x3c/0x80
[ 1.616286] [df4a5c18] [c005fe2c] irq_free_descs+0x70/0xa8
[ 1.621778] [df4a5c38] [c033d3fc] of_fsl_spi_probe+0xdc/0x3cc
[ 1.627525] [df4a5c88] [c02f0f64] platform_drv_probe+0x44/0xa4
[ 1.633350] [df4a5c98] [c02eee44] really_probe+0x1ac/0x418
[ 1.638829] [df4a5cc8] [c02ed3e8] bus_for_each_drv+0x64/0xb0
[ 1.644481] [df4a5cf8] [c02ef950] __device_attach+0xd4/0x128
[ 1.650132] [df4a5d28] [c02ed61c] bus_probe_device+0xa0/0xbc
[ 1.655783] [df4a5d48] [c02ebbe8] device_add+0x544/0x74c
[ 1.661096] [df4a5d88] [c0382b78] of_platform_device_create_pdata+0xa4/0x100
[ 1.668131] [df4a5da8] [c0382cf4] of_platform_bus_create+0x120/0x20c
[ 1.674474] [df4a5df8] [c0382d50] of_platform_bus_create+0x17c/0x20c
[ 1.680818] [df4a5e48] [c0382e88] of_platform_bus_probe+0x9c/0xf0
[ 1.686907] [df4a5e68] [c0751404] __machine_initcall_cmpcpro_cmpcpro_declare_of_platform_devices+0x74/0x1a4
[ 1.696629] [df4a5e98] [c072a4cc] do_one_initcall+0x8c/0x1d4
[ 1.702282] [df4a5ef8] [c072a768] kernel_init_freeable+0x154/0x204
[ 1.708455] [df4a5f28] [c0004b2c] kernel_init+0x18/0x110
[ 1.713769] [df4a5f38] [c00122ac] ret_from_kernel_thread+0x14/0x1c
[ 1.719926] Instruction dump:
[ 1.722889] 2c030000 4182004c 3863ffb0 3c80c05f 80e3005c 388436a0 3c60c06d 7fa6eb78
[ 1.730630] 7fe5fb78 38840280 38634178 4be8c611 <0fe00000> 4bffff6c 3c60c071 7fe4fb78
[ 1.738556] ---[ end trace 05d0720bf2e352e2 ]---

The problem comes from the error path which calls
irq_dispose_mapping() while the IRQ has been requested with
devm_request_irq().

IRQ doesn't need to be mapped with irq_of_parse_and_map(). The only
need is to get the IRQ virtual number. For that, use
of_irq_to_resource() instead of the
irq_of_parse_and_map()/irq_dispose_mapping() pair.

Fixes: 500a32abaf81 ("spi: fsl: Call irq_dispose_mapping in err path")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
drivers/spi/spi-fsl-spi.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c
index e2d878397efd..2d85c81983b1 100644
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -765,8 +765,8 @@ static int of_fsl_spi_probe(struct platform_device *ofdev)
if (ret)
goto err;

- irq = irq_of_parse_and_map(np, 0);
- if (!irq) {
+ irq = of_irq_to_resource(np, 0, NULL);
+ if (irq <= 0) {
ret = -EINVAL;
goto err;
}
@@ -780,7 +780,6 @@ static int of_fsl_spi_probe(struct platform_device *ofdev)
return 0;

err:
- irq_dispose_mapping(irq);
return ret;
}

--
2.13.3