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mxser: extract TX empty check from mxser_wait_until_sent()
And move it to new mxser_tx_empty(), because: 1) it simplifies the code (esp. the locking), and 2) serial_core needs such a hook anyway, so have it ready. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20211118073125.12283-12-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@ -1402,6 +1402,18 @@ static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termi
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}
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}
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static bool mxser_tx_empty(struct mxser_port *info)
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{
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unsigned long flags;
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u8 lsr;
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spin_lock_irqsave(&info->slock, flags);
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lsr = inb(info->ioaddr + UART_LSR);
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spin_unlock_irqrestore(&info->slock, flags);
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return !(lsr & UART_LSR_TEMT);
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}
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/*
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* mxser_wait_until_sent() --- wait until the transmitter is empty
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*/
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@ -1409,8 +1421,6 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
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{
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struct mxser_port *info = tty->driver_data;
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unsigned long orig_jiffies, char_time;
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unsigned long flags;
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int lsr;
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if (info->type == PORT_UNKNOWN)
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return;
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@ -1445,17 +1455,13 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
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if (!timeout || timeout > 2 * info->timeout)
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timeout = 2 * info->timeout;
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spin_lock_irqsave(&info->slock, flags);
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while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {
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spin_unlock_irqrestore(&info->slock, flags);
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while (mxser_tx_empty(info)) {
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schedule_timeout_interruptible(char_time);
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spin_lock_irqsave(&info->slock, flags);
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if (signal_pending(current))
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break;
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if (timeout && time_after(jiffies, orig_jiffies + timeout))
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break;
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}
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spin_unlock_irqrestore(&info->slock, flags);
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set_current_state(TASK_RUNNING);
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}
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