From 09498087f922bb623b66db9e89c6fd11a3799867 Mon Sep 17 00:00:00 2001 From: Heiko Stuebner Date: Thu, 9 Mar 2017 07:41:16 +0100 Subject: serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios clk_round_rate returns a signed long and may possibly return errors in it, for example if there is no possible rate. Till now dw8250_set_termios ignored any error, the signednes and would just use the value as input to clk_set_rate. This of course falls apart if there is an actual error, so check for errors and only try to set a rate if the value is actually valid. This turned up on some Rockchip platforms after commit 6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be used") enabled set_termios callback in all cases, not only ACPI. Fixes: 6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be used") Signed-off-by: Heiko Stuebner Reviewed-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_dw.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/tty/serial') diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 6ee55a2..223ac23 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -257,7 +257,7 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, { unsigned int baud = tty_termios_baud_rate(termios); struct dw8250_data *d = p->private_data; - unsigned int rate; + long rate; int ret; if (IS_ERR(d->clk) || !old) @@ -265,7 +265,10 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, clk_disable_unprepare(d->clk); rate = clk_round_rate(d->clk, baud * 16); - ret = clk_set_rate(d->clk, rate); + if (rate < 0) + ret = rate; + else + ret = clk_set_rate(d->clk, rate); clk_prepare_enable(d->clk); if (!ret) -- cgit v1.1 From b15bfbe6427712d1b992bf806a6df9c05002a0a4 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Sat, 4 Mar 2017 13:09:58 +0000 Subject: serial: 8250_dw: Fix breakage when HAVE_CLK=n Commit 6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be used") recently broke the 8250_dw driver on platforms which don't select HAVE_CLK, as dw8250_set_termios() gets confused by the behaviour of the fallback HAVE_CLK=n clock API in linux/clk.h which pretends everything is fine but returns (valid) NULL clocks and 0 HZ clock rates. That 0 rate is written into the uartclk resulting in a crash at boot, e.g. on Cavium Octeon III based UTM-8 we get something like this: 1180000000800.serial: ttyS0 at MMIO 0x1180000000800 (irq = 41, base_baud = 25000000) is a OCTEON ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1 at drivers/tty/serial/serial_core.c:441 uart_get_baud_rate+0xfc/0x1f0 ... Call Trace: ... [] uart_get_baud_rate+0xfc/0x1f0 [] serial8250_do_set_termios+0xb0/0x440 [] uart_set_options+0xe8/0x190 [] serial8250_console_setup+0x84/0x158 [] univ8250_console_setup+0x54/0x70 [] register_console+0x1c8/0x418 [] uart_add_one_port+0x434/0x4b0 [] serial8250_register_8250_port+0x2d8/0x440 [] dw8250_probe+0x388/0x5e8 ... The clock API is defined such that NULL is a valid clock handle so it wouldn't be right to check explicitly for NULL. Instead treat a clk_round_rate() return value of 0 as an error which prevents uartclk being overwritten. Fixes: 6a171b299379 ("serial: 8250_dw: Allow hardware flow control to be used") Signed-off-by: James Hogan Cc: Kefeng Wang Cc: David Daney Cc: Russell King Cc: linux-serial@vger.kernel.org Cc: linux-clk@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: bcm-kernel-feedback-list@broadcom.com Reviewed-by: Andy Shevchenko Reviewed-by: Jason Uy Reviewed-by: Heiko Stuebner Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_dw.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/tty/serial') diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 223ac23..e65808c 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -267,6 +267,8 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios, rate = clk_round_rate(d->clk, baud * 16); if (rate < 0) ret = rate; + else if (rate == 0) + ret = -ENOENT; else ret = clk_set_rate(d->clk, rate); clk_prepare_enable(d->clk); -- cgit v1.1 From b767ad726c2aa6219318bf0da83fbe690e653d9a Mon Sep 17 00:00:00 2001 From: Aleksey Makarov Date: Wed, 1 Mar 2017 18:23:02 +0300 Subject: Revert "tty: serial: pl011: add ttyAMA for matching pl011 console" The original patch makes the condition always true, so it is wrong. It masks (but not fixes) the bug described in the commit message but introduces a regression (no console is selected by SPCR) in regular (no 'console=ttyAMA') case. s/||/&&/ would not fix the problem as the root cause was identified incorrectly. This reverts commit aea9a80ba98a0c9b4de88850260e9fbdcc98360b. Signed-off-by: Aleksey Makarov Signed-off-by: Greg Kroah-Hartman Acked-by: Sudeep Holla Tested-by: Jayachandran C Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/amba-pl011.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty/serial') diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 8789ea4..56f92d7 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2373,7 +2373,7 @@ static int __init pl011_console_match(struct console *co, char *name, int idx, if (strcmp(name, "qdf2400_e44") == 0) { pr_info_once("UART: Working around QDF2400 SoC erratum 44"); qdf2400_e44_present = true; - } else if (strcmp(name, "pl011") != 0 || strcmp(name, "ttyAMA") != 0) { + } else if (strcmp(name, "pl011") != 0) { return -ENODEV; } -- cgit v1.1