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* [PATCH] serial: 8250_pnp: pass IRQ shared flag to UART ports
@ 2020-02-09  4:42 Li RongQing
  2020-02-10 10:09 ` Andy Shevchenko
  0 siblings, 1 reply; 4+ messages in thread
From: Li RongQing @ 2020-02-09  4:42 UTC (permalink / raw)
  To: gregkh, jslaby, haolee.swjtu, andriy.shevchenko, linux-serial

On some systems IRQ lines might be shared between multiple devices.
If so, the irqflags have to be configured accordingly. The reason is:
The 8250 port startup code performs IRQ tests *before* the IRQ handler
for that particular port is registered.

This commit fixed the below issue:
[  973.782131] 8250 request irq 00000000f5a0e2ae 00000000f5a0e2ae 0
[  973.785414] genirq: Flags mismatch irq 16. 00000004 (ttyS0) vs. 00000084 (ipmi_si)
[  973.788741] CPU: 0 PID: 1 Comm: systemd Tainted: G            E     4.19.0-1.0.0.1.rc2 #5
[  973.792112] Hardware name: Huawei TaiShan 2280 V2/BC82AMDDA, BIOS 0.18 06/10/2019
[  973.795577] Call trace:
[  973.799018]  dump_backtrace+0x0/0x198
[  973.802493]  show_stack+0x24/0x30
[  973.805965]  dump_stack+0x9c/0xbc
[  973.809357]  __setup_irq+0x150/0x6c0
[  973.812663]  request_threaded_irq+0xe8/0x180
[  973.815891]  univ8250_setup_irq+0x278/0x2a0
[  973.819007]  serial8250_do_startup+0x468/0x818
[  973.822060]  serial8250_startup+0x38/0x48
[  973.825099]  uart_startup.part.9+0x11c/0x270
[  973.828156]  uart_port_activate+0x64/0x98
[  973.831247]  tty_port_open+0xac/0x110
[  973.834349]  uart_open+0x2c/0x40
[  973.837415]  tty_open+0x110/0x3f8
[  973.840464]  chrdev_open+0xc8/0x248
[  973.843584]  do_dentry_open+0x118/0x358
[  973.846615]  vfs_open+0x38/0x48
[  973.849621]  do_last+0x23c/0x808
[  973.852610]  path_openat+0x88/0x260
[  973.855596]  do_filp_open+0x88/0x100
[  973.858582]  do_sys_open+0x188/0x218
[  973.861564]  __arm64_sys_openat+0x2c/0x38
[  973.864575]  el0_svc_common+0xac/0x178
[  973.867592]  el0_svc_handler+0x38/0x78
[  973.870570]  el0_svc+0x8/0xc

Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
 drivers/tty/serial/8250/8250_pnp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index de90d681b64c..10c260928952 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -476,6 +476,7 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 		uart.port.flags |= UPF_SHARE_IRQ;
 	uart.port.uartclk = 1843200;
 	uart.port.dev = &dev->dev;
+	uart.port.irqflags |= IRQF_SHARED;
 
 	line = serial8250_register_8250_port(&uart);
 	if (line < 0 || (flags & CIR_PORT))
-- 
2.16.2


^ permalink raw reply	[flat|nested] 4+ messages in thread

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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-09  4:42 [PATCH] serial: 8250_pnp: pass IRQ shared flag to UART ports Li RongQing
2020-02-10 10:09 ` Andy Shevchenko
2020-02-10 12:54   ` 答复: " Li,Rongqing
2020-02-11 13:47     ` Andy Shevchenko

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