| Message ID | 20211230102110.3861-7-yu.tu@amlogic.com |
|---|---|
| State | New |
| Headers | show |
| Series | the UART driver compatible with the Amlogic Meson | expand |
On Thu, Dec 30, 2021 at 11:22 AM Yu Tu <yu.tu@amlogic.com> wrote: > > Because an interrupt error occurs when the user opens /dev/ttyAML* but > don't close it, and then opens the same port again. This problem is > encountered in actual projects. I would like to hear from the serial driver maintainers whether the described problem is a userspace or driver bug. If it's a driver bug then this should be sent as a separate patch (unrelated to this series) with a fixes tag. [...] > + ret = devm_request_irq(&pdev->dev, port->irq, meson_uart_interrupt, > + 0, dev_name(&pdev->dev), port); You can replace dev_name(&pdev->dev) with NULL to achieve the same result with less code. dev_name(dev) is the default value, see [0] Best regards, Martin [0] https://elixir.bootlin.com/linux/v5.15/source/kernel/irq/devres.c#L64
On 2021/12/31 6:41, Martin Blumenstingl wrote: > [ EXTERNAL EMAIL ] > > On Thu, Dec 30, 2021 at 11:22 AM Yu Tu <yu.tu@amlogic.com> wrote: >> >> Because an interrupt error occurs when the user opens /dev/ttyAML* but >> don't close it, and then opens the same port again. This problem is >> encountered in actual projects. > I would like to hear from the serial driver maintainers whether the > described problem is a userspace or driver bug. > > If it's a driver bug then this should be sent as a separate patch > (unrelated to this series) with a fixes tag. > > [...] >> + ret = devm_request_irq(&pdev->dev, port->irq, meson_uart_interrupt, >> + 0, dev_name(&pdev->dev), port); > You can replace dev_name(&pdev->dev) with NULL to achieve the same > result with less code. > dev_name(dev) is the default value, see [0] > I think you are right, I will remove this patch. I learned a lot. > > Best regards, > Martin > > > [0] https://elixir.bootlin.com/linux/v5.15/source/kernel/irq/devres.c#L64 >
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c index 45e41f20cba3..0dd3f5b35768 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -135,8 +135,6 @@ static void meson_uart_shutdown(struct uart_port *port) unsigned long flags; u32 val; - free_irq(port->irq, port); - spin_lock_irqsave(&port->lock, flags); val = readl(port->membase + AML_UART_CONTROL); @@ -284,7 +282,6 @@ static void meson_uart_reset(struct uart_port *port) static int meson_uart_startup(struct uart_port *port) { u32 val; - int ret; meson_uart_reset(port); @@ -298,10 +295,7 @@ static int meson_uart_startup(struct uart_port *port) val = (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port->fifosize / 2)); writel(val, port->membase + AML_UART_MISC); - ret = request_irq(port->irq, meson_uart_interrupt, 0, - port->name, port); - - return ret; + return 0; } static void meson_uart_change_speed(struct uart_port *port, unsigned long baud) @@ -908,6 +902,14 @@ static int meson_uart_probe(struct platform_device *pdev) meson_ports[pdev->id] = port; platform_set_drvdata(pdev, port); + ret = devm_request_irq(&pdev->dev, port->irq, meson_uart_interrupt, + 0, dev_name(&pdev->dev), port); + if (ret) { + dev_err(&pdev->dev, "failed to request uart irq: %d\n", + ret); + return ret; + } + /* reset port before registering (and possibly registering console) */ meson_uart_reset(port);
Because an interrupt error occurs when the user opens /dev/ttyAML* but don't close it, and then opens the same port again. This problem is encountered in actual projects. Signed-off-by: Yu Tu <yu.tu@amlogic.com> --- drivers/tty/serial/meson_uart.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)