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From:   Anders Roxell <anders.roxell@linaro.org>
To:     will.deacon@arm.com, mark.rutland@arm.com, catalin.marinas@arm.com
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Anders Roxell <anders.roxell@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH] arm64: perf: set suppress_bind_attrs flag to true
Date:   Wed, 17 Oct 2018 17:26:22 +0200
Message-Id: <20181017152622.15717-1-anders.roxell@linaro.org>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
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The armv8_pmuv3 driver doesn't have a remove function, and when the test
'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, the following Call trace
can be seen.

[    1.424287] Failed to register pmu: armv8_pmuv3, reason -17
[    1.424870] WARNING: CPU: 0 PID: 1 at ../kernel/events/core.c:11771 perf_event_sysfs_init+0x98/0xdc
[    1.425220] Modules linked in:
[    1.425531] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W         4.19.0-rc7-next-20181012-00003-ge7a97b1ad77b-dirty #35
[    1.425951] Hardware name: linux,dummy-virt (DT)
[    1.426212] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    1.426458] pc : perf_event_sysfs_init+0x98/0xdc
[    1.426720] lr : perf_event_sysfs_init+0x98/0xdc
[    1.426908] sp : ffff00000804bd50
[    1.427077] x29: ffff00000804bd50 x28: ffff00000934e078
[    1.427429] x27: ffff000009546000 x26: 0000000000000007
[    1.427757] x25: ffff000009280710 x24: 00000000ffffffef
[    1.428086] x23: ffff000009408000 x22: 0000000000000000
[    1.428415] x21: ffff000009136008 x20: ffff000009408730
[    1.428744] x19: ffff80007b20b400 x18: 000000000000000a
[    1.429075] x17: 0000000000000000 x16: 0000000000000000
[    1.429418] x15: 0000000000000400 x14: 2e79726f74636572
[    1.429748] x13: 696420656d617320 x12: 656874206e692065
[    1.430060] x11: 6d616e20656d6173 x10: 2065687420687469
[    1.430335] x9 : ffff00000804bd50 x8 : 206e6f7361657220
[    1.430610] x7 : 2c3376756d705f38 x6 : ffff00000954d7ce
[    1.430880] x5 : 0000000000000000 x4 : 0000000000000000
[    1.431226] x3 : 0000000000000000 x2 : ffffffffffffffff
[    1.431554] x1 : 4d151327adc50b00 x0 : 0000000000000000
[    1.431868] Call trace:
[    1.432102]  perf_event_sysfs_init+0x98/0xdc
[    1.432382]  do_one_initcall+0x6c/0x1a8
[    1.432637]  kernel_init_freeable+0x1bc/0x280
[    1.432905]  kernel_init+0x18/0x160
[    1.433115]  ret_from_fork+0x10/0x18
[    1.433297] ---[ end trace 27fd415390eb9883 ]---

Rework to set suppress_bind_attrs flag to avoid removing the device when
CONFIG_DEBUG_TEST_DRIVER_REMOVE=y, since there's no real reason to
remove the armv8_pmuv3 driver.

Cc: Arnd Bergmann <arnd@arndb.de>
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
---
 arch/arm64/kernel/perf_event.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 8e38d5267f22..5ffcb54fde3f 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -1267,6 +1267,7 @@ static struct platform_driver armv8_pmu_driver = {
 	.driver		= {
 		.name	= ARMV8_PMU_PDEV_NAME,
 		.of_match_table = armv8_pmu_of_device_ids,
+		.suppress_bind_attrs = true,
 	},
 	.probe		= armv8_pmu_device_probe,
 };
-- 
2.19.1