| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Wed, 25 May 2022 16:37:32 +0300
From: Claudiu Beznea <claudiu.beznea@...rochip.com>
To: <richard.genoud@...il.com>, <gregkh@...uxfoundation.org>,
<jirislaby@...nel.org>, <nicolas.ferre@...rochip.com>,
<alexandre.belloni@...tlin.com>, <patrice.chotard@...s.st.com>
CC: <linux-serial@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>,
Claudiu Beznea <claudiu.beznea@...rochip.com>
Subject: [PATCH 2/3] tty: serial: atmel: improve clock management
atmel_port->clk was requested in atmel_init_port() (which is called only
on probe path) only if atmel_port->clk was NULL. But atmel_port->clk is
NULL on probing path. Thus don't check this. Along with this the clock is
now requested with devm_clk_get() and the clock request has been moved in
atmel_serial_probe() function to avoid disabling/re-enabling it on probe
path for multiple times. All the checks of atmel_port->clk were removed
along with clk_put() and atmel_port->clk = NULL. Now, on probing time the
clock is enabled at the beginning and disabled at the end of probe. As
atmel_console_setup() is called in the middle of probe and clock is
already enabled at that time the clk_prepare_enable() in
atmel_console_setup() has also been removed.
Signed-off-by: Claudiu Beznea <claudiu.beznea@...rochip.com>
---
drivers/tty/serial/atmel_serial.c | 65 +++++++------------------------
1 file changed, 15 insertions(+), 50 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 5c793a23dc54..2955b1012014 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2501,24 +2501,7 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
if (ret)
return ret;
- /* for console, the clock could already be configured */
- if (!atmel_port->clk) {
- atmel_port->clk = clk_get(&mpdev->dev, "usart");
- if (IS_ERR(atmel_port->clk)) {
- ret = PTR_ERR(atmel_port->clk);
- atmel_port->clk = NULL;
- return ret;
- }
- ret = clk_prepare_enable(atmel_port->clk);
- if (ret) {
- clk_put(atmel_port->clk);
- atmel_port->clk = NULL;
- return ret;
- }
- port->uartclk = clk_get_rate(atmel_port->clk);
- clk_disable_unprepare(atmel_port->clk);
- /* only enable clock when USART is in use */
- }
+ port->uartclk = clk_get_rate(atmel_port->clk);
/*
* Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or
@@ -2640,10 +2623,6 @@ static int __init atmel_console_setup(struct console *co, char *options)
return -ENODEV;
}
- ret = clk_prepare_enable(atmel_ports[co->index].clk);
- if (ret)
- return ret;
-
atmel_uart_writel(port, ATMEL_US_IDR, -1);
atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
@@ -2889,14 +2868,23 @@ static int atmel_serial_probe(struct platform_device *pdev)
atomic_set(&atmel_port->tasklet_shutdown, 0);
spin_lock_init(&atmel_port->lock_suspended);
+ atmel_port->clk = devm_clk_get(&pdev->dev, "usart");
+ if (IS_ERR(atmel_port->clk)) {
+ ret = PTR_ERR(atmel_port->clk);
+ goto err;
+ }
+ ret = clk_prepare_enable(atmel_port->clk);
+ if (ret)
+ goto err;
+
ret = atmel_init_port(atmel_port, pdev);
if (ret)
- goto err_clear_bit;
+ goto err_clk_disable_unprepare;
atmel_port->gpios = mctrl_gpio_init(&atmel_port->uart, 0);
if (IS_ERR(atmel_port->gpios)) {
ret = PTR_ERR(atmel_port->gpios);
- goto err_clear_bit;
+ goto err_clk_disable_unprepare;
}
if (!atmel_use_pdc_rx(&atmel_port->uart)) {
@@ -2905,7 +2893,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
sizeof(struct atmel_uart_char),
GFP_KERNEL);
if (!data)
- goto err_alloc_ring;
+ goto err_clk_disable_unprepare;
atmel_port->rx_ring.buf = data;
}
@@ -2915,26 +2903,9 @@ static int atmel_serial_probe(struct platform_device *pdev)
if (ret)
goto err_add_port;
-#ifdef CONFIG_SERIAL_ATMEL_CONSOLE
- if (uart_console(&atmel_port->uart)
- && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
- /*
- * The serial core enabled the clock for us, so undo
- * the clk_prepare_enable() in atmel_console_setup()
- */
- clk_disable_unprepare(atmel_port->clk);
- }
-#endif
-
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, atmel_port);
- /*
- * The peripheral clock has been disabled by atmel_init_port():
- * enable it before accessing I/O registers
- */
- clk_prepare_enable(atmel_port->clk);
-
if (rs485_enabled) {
atmel_uart_writel(&atmel_port->uart, ATMEL_US_MR,
ATMEL_US_USMODE_NORMAL);
@@ -2958,12 +2929,8 @@ static int atmel_serial_probe(struct platform_device *pdev)
err_add_port:
kfree(atmel_port->rx_ring.buf);
atmel_port->rx_ring.buf = NULL;
-err_alloc_ring:
- if (!uart_console(&atmel_port->uart)) {
- clk_put(atmel_port->clk);
- atmel_port->clk = NULL;
- }
-err_clear_bit:
+err_clk_disable_unprepare:
+ clk_disable_unprepare(atmel_port->clk);
clear_bit(atmel_port->uart.line, atmel_ports_in_use);
err:
return ret;
@@ -2997,8 +2964,6 @@ static int atmel_serial_remove(struct platform_device *pdev)
clear_bit(port->line, atmel_ports_in_use);
- clk_put(atmel_port->clk);
- atmel_port->clk = NULL;
pdev->dev.of_node = NULL;
return ret;
--
2.34.1
Powered by blists - more mailing lists