[PATCH v4 2/2] serial/amba-pl011: Refactor and simplify TX FIFO handling

[Jakub Kiciński]

On Fri, 27 Mar 2015 14:59:31 +0000, Dave Martin wrote:
> Commit 734745c serial/amba-pl011: Activate TX IRQ passively
> adds some unnecessary complexity and overhead in the form of
> a softirq mechanism for transmitting in the absence of interrupts.
> 
> After some discussion [1], this turns out to be unnecessary.
> 
> This patch simplifies the code flow to reduce the reliance on
> subtle behaviour and avoid fragility under future maintenance.
> 
> To this end, the TX softirq mechanism is removed and instead
> pl011_start_tx() will now simply stuff the FIFO until full
> (guaranteeing future TX IRQs), or until there are no more chars
> to write (in which case we don't care whether an IRQ happens).
> 
> [1] Thanks to Jakub Kiciński for his input and similar patch.
> 
> Signed-off-by: Dave Martin <Dave.Martin at arm.com>

Signed-off-by: Jakub Kicinski <kubakici at wp.pl>