From: Xingxing Su <suxingxing@loongson.cn>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] PCI: Don't use Printk in raw_spinlocks
Date: Sat, 1 Aug 2020 09:25:49 +0800 [thread overview]
Message-ID: <1596245149-28628-1-git-send-email-suxingxing@loongson.cn> (raw)
Do not use printk in raw_spinlocks,
it will cause BUG: Invalid wait context.
The trace reported by lockdep follows.
[ 2.986113] =============================
[ 2.986115] [ BUG: Invalid wait context ]
[ 2.986116] 5.8.0-rc1+ #11 Not tainted
[ 2.986118] -----------------------------
[ 2.986120] swapper/0/1 is trying to lock:
[ 2.986122] ffffffff80f5ddd8 (console_owner){....}-{3:3}, at: console_unlock+0x284/0x820
[ 2.986130] other info that might help us debug this:
[ 2.986132] context-{5:5}
[ 2.986134] 3 locks held by swapper/0/1:
[ 2.986135] #0: 98000007fa03c990 (&dev->mutex){....}-{0:0}, at: device_driver_attach+0x28/0x90
[ 2.986144] #1: ffffffff80fb83a8 (pci_lock){....}-{2:2}, at: pci_bus_write_config_word+0x60/0xb8
[ 2.986152] #2: ffffffff80f5ded0 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0x1b0/0x3b8
[ 2.986161] stack backtrace:
[ 2.986163] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1+ #11
[ 2.986164] Stack : 0000000000001d67 98000000030be9b0 0000000000000001 7b2aba74f6c4785b
[ 2.986172] 7b2aba74f6c4785b 0000000000000000 98000007f89cb438 ffffffff80e7dc80
[ 2.986181] 0000000000000001 000000000000000a 0000000000000001 0000000000000001
[ 2.986189] ffffffff80f4e156 fffffffffffffffd ffffffff80cc2d98 fffffffff8000000
[ 2.986197] 0000000024000000 ffffffff80f40000 0000000000000000 0000000000000000
[ 2.986205] ffffffff9500cce0 0000000000000000 ffffffff80f50000 ffffffff81546318
[ 2.986213] ffffffff81c4c3c0 0000000000000018 ffffffffbc000000 0000000000000000
[ 2.986221] ffffffff81340000 98000007f89c8000 98000007f89cb430 98000007f8a00000
[ 2.986229] ffffffff806be568 0000000000000000 0000000000000000 0000000000000000
[ 2.986237] 0000000000000000 0000000000000000 ffffffff80211c1c 7b2aba74f6c4785b
[ 2.986245] ...
[ 2.986250] Call Trace:
[ 2.986251] [<ffffffff80211c1c>] show_stack+0x9c/0x130
[ 2.986253] [<ffffffff806be568>] dump_stack+0xe8/0x150
[ 2.986255] [<ffffffff802ad408>] __lock_acquire+0x570/0x3250
[ 2.986257] [<ffffffff802abed0>] lock_acquire+0x118/0x558
[ 2.986259] [<ffffffff802be764>] console_unlock+0x2e4/0x820
[ 2.986261] [<ffffffff802c0a68>] vprintk_emit+0x1c0/0x3b8
[ 2.986263] [<ffffffff807f45a8>] dev_vprintk_emit+0x1c8/0x210
[ 2.986265] [<ffffffff807f462c>] dev_printk_emit+0x3c/0x60
[ 2.986267] [<ffffffff807f499c>] _dev_warn+0x5c/0x80
[ 2.986269] [<ffffffff806eea9c>] pci_generic_config_write32+0x154/0x160
[ 2.986271] [<ffffffff806edca4>] pci_bus_write_config_word+0x84/0xb8
[ 2.986273] [<ffffffff806f1664>] pci_setup_device+0x22c/0x768
[ 2.986275] [<ffffffff806f26a0>] pci_scan_single_device+0xc8/0x100
[ 2.986277] [<ffffffff806f2788>] pci_scan_slot+0xb0/0x178
[ 2.986279] [<ffffffff806f3ae4>] pci_scan_child_bus_extend+0x5c/0x370
[ 2.986281] [<ffffffff806f407c>] pci_scan_root_bus_bridge+0x6c/0xf0
[ 2.986283] [<ffffffff806f411c>] pci_host_probe+0x1c/0xd8
[ 2.986285] [<ffffffff807fa03c>] platform_drv_probe+0x54/0xb8
[ 2.986287] [<ffffffff807f71f8>] really_probe+0x130/0x388
[ 2.986289] [<ffffffff807f7594>] driver_probe_device+0x64/0xd8
[ 2.986291] [<ffffffff807f7844>] device_driver_attach+0x84/0x90
[ 2.986293] [<ffffffff807f7918>] __driver_attach+0xc8/0x128
[ 2.986295] [<ffffffff807f4cac>] bus_for_each_dev+0x74/0xd8
[ 2.986297] [<ffffffff807f6408>] bus_add_driver+0x170/0x250
[ 2.986299] [<ffffffff807f899c>] driver_register+0x84/0x150
[ 2.986301] [<ffffffff80200b08>] do_one_initcall+0x98/0x458
[ 2.986303] [<ffffffff810212dc>] kernel_init_freeable+0x2c0/0x36c
[ 2.986305] [<ffffffff80be7540>] kernel_init+0x10/0x128
[ 2.986307] [<ffffffff80209d44>] ret_from_kernel_thread+0x14/0x1c
Signed-off-by: Xingxing Su <suxingxing@loongson.cn>
---
drivers/pci/access.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 79c4a2e..b3fc164 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -160,9 +160,6 @@ int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn,
* write happen to have any RW1C (write-one-to-clear) bits set, we
* just inadvertently cleared something we shouldn't have.
*/
- dev_warn_ratelimited(&bus->dev, "%d-byte config write to %04x:%02x:%02x.%d offset %#x may corrupt adjacent RW1C bits\n",
- size, pci_domain_nr(bus), bus->number,
- PCI_SLOT(devfn), PCI_FUNC(devfn), where);
mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
tmp = readl(addr) & mask;
--
2.1.0
next reply other threads:[~2020-08-01 1:25 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-01 1:25 Xingxing Su [this message]
2020-09-10 2:07 ` [PATCH] PCI: Don't use Printk in raw_spinlocks Bjorn Helgaas
2020-09-10 14:21 ` Rob Herring
2020-09-10 16:07 ` Scott Branden
2020-09-10 18:46 ` Bjorn Helgaas
2020-09-10 18:50 ` Florian Fainelli
2020-09-10 19:20 ` Bjorn Helgaas
2020-09-10 19:22 ` Florian Fainelli
2021-03-30 20:53 ` Tyler Hicks
2021-06-14 17:43 ` Tyler Hicks
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