From: Russell King <rmk+kernel@armlinux.org.uk> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Jiri Slaby <jslaby@suse.com> Cc: linux-arm-kernel@lists.infradead.org, linux-serial@vger.kernel.org Subject: [PATCH] tty: serial: 21285: fix lockup on open Date: Sun, 18 Oct 2020 09:42:04 +0100 [thread overview] Message-ID: <E1kU4GS-0006lE-OO@rmk-PC.armlinux.org.uk> (raw) Commit 293f89959483 ("tty: serial: 21285: stop using the unused[] variable from struct uart_port") introduced a bug which stops the transmit interrupt being disabled when there are no characters to transmit - disabling the transmit interrupt at the interrupt controller is the only way to stop an interrupt storm. If this interrupt is not disabled when there are no transmit characters, we end up with an interrupt storm which prevents the machine making forward progress. Fixes: 293f89959483 ("tty: serial: 21285: stop using the unused[] variable from struct uart_port") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> --- drivers/tty/serial/21285.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c index 718e010fcb04..09baef4ccc39 100644 --- a/drivers/tty/serial/21285.c +++ b/drivers/tty/serial/21285.c @@ -50,25 +50,25 @@ static const char serial21285_name[] = "Footbridge UART"; static bool is_enabled(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - if (test_bit(bit, &private_data)) + if (test_bit(bit, private_data)) return true; return false; } static void enable(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - set_bit(bit, &private_data); + set_bit(bit, private_data); } static void disable(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - clear_bit(bit, &private_data); + clear_bit(bit, private_data); } #define is_tx_enabled(port) is_enabled(port, tx_enabled_bit) -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Russell King <rmk+kernel@armlinux.org.uk> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] tty: serial: 21285: fix lockup on open Date: Sun, 18 Oct 2020 09:42:04 +0100 [thread overview] Message-ID: <E1kU4GS-0006lE-OO@rmk-PC.armlinux.org.uk> (raw) Commit 293f89959483 ("tty: serial: 21285: stop using the unused[] variable from struct uart_port") introduced a bug which stops the transmit interrupt being disabled when there are no characters to transmit - disabling the transmit interrupt at the interrupt controller is the only way to stop an interrupt storm. If this interrupt is not disabled when there are no transmit characters, we end up with an interrupt storm which prevents the machine making forward progress. Fixes: 293f89959483 ("tty: serial: 21285: stop using the unused[] variable from struct uart_port") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> --- drivers/tty/serial/21285.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c index 718e010fcb04..09baef4ccc39 100644 --- a/drivers/tty/serial/21285.c +++ b/drivers/tty/serial/21285.c @@ -50,25 +50,25 @@ static const char serial21285_name[] = "Footbridge UART"; static bool is_enabled(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - if (test_bit(bit, &private_data)) + if (test_bit(bit, private_data)) return true; return false; } static void enable(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - set_bit(bit, &private_data); + set_bit(bit, private_data); } static void disable(struct uart_port *port, int bit) { - unsigned long private_data = (unsigned long)port->private_data; + unsigned long *private_data = (unsigned long *)&port->private_data; - clear_bit(bit, &private_data); + clear_bit(bit, private_data); } #define is_tx_enabled(port) is_enabled(port, tx_enabled_bit) -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-10-18 8:42 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-18 8:42 Russell King [this message] 2020-10-18 8:42 ` [PATCH] tty: serial: 21285: fix lockup on open Russell King 2020-10-19 7:00 ` Greg Kroah-Hartman 2020-10-19 7:00 ` Greg Kroah-Hartman
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=E1kU4GS-0006lE-OO@rmk-PC.armlinux.org.uk \ --to=rmk+kernel@armlinux.org.uk \ --cc=gregkh@linuxfoundation.org \ --cc=jslaby@suse.com \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-serial@vger.kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.