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 Kici?ski for his input and similar patch.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>

Signed-off-by: Jakub Kicinski <redacted>