Re: Patch "serial: pch: Don't disable interrupts while acquiring lock in ISR." has been added to the 6.1-stable tree

[Jiri Slaby <jirislaby@kernel.org>]

On 21. 08. 24, 15:37, Sasha Levin wrote:
> This is a note to let you know that I've just added the patch titled
> 
>      serial: pch: Don't disable interrupts while acquiring lock in ISR.
> 
> to the 6.1-stable tree which can be found at:
>      http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> 
> The filename of the patch is:
>       serial-pch-don-t-disable-interrupts-while-acquiring-.patch
> and it can be found in the queue-6.1 subdirectory.
> 
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.

I feel so. It does not fix anything real. It is a prep for 
d47dd323bf959. So unless you take that too, this one does not make sense 
on its own.

> commit 2e7194802a740ab6ef47e19e56bd1b06c03610d3
> Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Date:   Fri Mar 1 22:45:28 2024 +0100
> 
>      serial: pch: Don't disable interrupts while acquiring lock in ISR.
>      
>      [ Upstream commit f8ff23ebce8c305383c8070e1ea3b08a69eb1e8d ]
>      
>      The interrupt service routine is always invoked with disabled
>      interrupts.
>      
>      Remove the _irqsave() from the locking functions in the interrupts
>      service routine/ pch_uart_interrupt().
>      
>      Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
>      Link: https://lore.kernel.org/r/20240301215246.891055-16-bigeasy@linutronix.de
>      Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>      Signed-off-by: Sasha Levin <sashal@kernel.org>
> 
> diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
> index abff1c6470f6a..d638e890ef6f0 100644
> --- a/drivers/tty/serial/pch_uart.c
> +++ b/drivers/tty/serial/pch_uart.c
> @@ -1023,11 +1023,10 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
>   	u8 lsr;
>   	int ret = 0;
>   	unsigned char iid;
> -	unsigned long flags;
>   	int next = 1;
>   	u8 msr;
>   
> -	spin_lock_irqsave(&priv->lock, flags);
> +	spin_lock(&priv->lock);
>   	handled = 0;
>   	while (next) {
>   		iid = pch_uart_hal_get_iid(priv);
> @@ -1087,7 +1086,7 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
>   		handled |= (unsigned int)ret;
>   	}
>   
> -	spin_unlock_irqrestore(&priv->lock, flags);
> +	spin_unlock(&priv->lock);
>   	return IRQ_RETVAL(handled);
>   }
>   

-- 
js
suse labs