2019-12-10 15:18:48

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v2 1/2] spi: fsl: don't map irq during probe

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.

To avoid build failure on SPARC which has a dummy version of
irq_of_parse_and_map() but not of of_irq_to_resource(), get this
driver dependent on OF_IRQ.

Reported-by: kbuild test robot <[email protected]>
[v2: adding dependency on CONFIG_OF_IRQ]
Fixes: 500a32abaf81 ("spi: fsl: Call irq_dispose_mapping in err path")
Cc: [email protected]

Signed-off-by: Christophe Leroy <[email protected]>
---
drivers/spi/Kconfig | 2 +-
drivers/spi/spi-fsl-spi.c | 5 ++---
2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 870f7797b56b..fba933f31d40 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -378,7 +378,7 @@ config SPI_FSL_CPM

config SPI_FSL_SPI
tristate "Freescale SPI controller and Aeroflex Gaisler GRLIB SPI controller"
- depends on OF
+ depends on OF_IRQ
select SPI_FSL_LIB
select SPI_FSL_CPM if FSL_SOC
help
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


2019-12-10 19:20:56

by Mark Brown

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] spi: fsl: don't map irq during probe

On Tue, Dec 10, 2019 at 03:17:15PM +0000, Christophe Leroy wrote:
> With lastest kernel, the following warning is observed at startup:

Please do not submit new versions of already applied patches, please
submit incremental updates to the existing code. Modifying existing
commits creates problems for other users building on top of those
commits so it's best practice to only change pubished git commits if
absolutely essential.


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