Unverified Commit 4a032c30 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!6851 serial/pmac_zilog: Remove flawed mitigation for rx irq flood 

Merge Pull Request from: @ci-robot 
 
PR sync from: Yi Yang <yiyang13@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/C5FBX2QTILIHG5RG57EH6H3A6AK2NLQ5/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9L5KR 
 
Link:https://gitee.com/openeuler/kernel/pulls/6851

 

Reviewed-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents 56e267ca 7e40e827

drivers/tty/serial/pmac_zilog.c

+0 −14
Original line number Diff line number Diff line
@@ -217,7 +217,6 @@ static bool pmz_receive_chars(struct uart_pmac_port *uap) 
{

	struct tty_port *port;

	unsigned char ch, r1, drop, flag;

	int loops = 0;



	/* Sanity check, make sure the old bug is no longer happening */

	if (uap->port.state == NULL) {
@@ -298,24 +297,11 @@ static bool pmz_receive_chars(struct uart_pmac_port *uap) 
		if (r1 & Rx_OVR)

			tty_insert_flip_char(port, 0, TTY_OVERRUN);

	next_char:

		/* We can get stuck in an infinite loop getting char 0 when the

		 * line is in a wrong HW state, we break that here.

		 * When that happens, I disable the receive side of the driver.

		 * Note that what I've been experiencing is a real irq loop where

		 * I'm getting flooded regardless of the actual port speed.

		 * Something strange is going on with the HW

		 */

		if ((++loops) > 1000)

			goto flood;

		ch = read_zsreg(uap, R0);

		if (!(ch & Rx_CH_AV))

			break;

	}



	return true;

 flood:

	pmz_interrupt_control(uap, 0);

	pmz_error("pmz: rx irq flood !\n");

	return true;

}