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From: "Jakub Kiciński" <moorray3@wp.pl>
To: Dave Martin <Dave.Martin@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrew Jackson <Andrew.Jackson@arm.com>,
	Graeme Gregory <gg@slimlogic.co.uk>,
	linux-serial@vger.kernel.org,
	Andre Przywara <Andre.Przywara@arm.com>,
	popcorn mix <popcornmix@gmail.com>,
	Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 2/2] serial/amba-pl011: Refactor and simplify TX FIFO handling
Date: Mon, 30 Mar 2015 16:28:11 +0200	[thread overview]
Message-ID: <20150330162811.3673482b@north> (raw)
In-Reply-To: <1427468371-11915-3-git-send-email-Dave.Martin@arm.com>

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@arm.com>

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

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WARNING: multiple messages have this Message-ID (diff)
From: moorray3@wp.pl (Jakub Kiciński)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 2/2] serial/amba-pl011: Refactor and simplify TX FIFO handling
Date: Mon, 30 Mar 2015 16:28:11 +0200	[thread overview]
Message-ID: <20150330162811.3673482b@north> (raw)
In-Reply-To: <1427468371-11915-3-git-send-email-Dave.Martin@arm.com>

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 <kubakici@wp.pl>

  parent reply	other threads:[~2015-03-30 14:28 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-27 14:59 [PATCH v4 0/2] serial/amba-pl011: Activate TX IRQ passively (rework) Dave Martin
2015-03-27 14:59 ` Dave Martin
2015-03-27 14:59 ` [PATCH v4 1/2] Revert "serial/amba-pl011: Leave the TX IRQ alone when the UART is not open" Dave Martin
2015-03-27 14:59   ` Dave Martin
2015-03-27 14:59 ` [PATCH v4 2/2] serial/amba-pl011: Refactor and simplify TX FIFO handling Dave Martin
2015-03-27 14:59   ` Dave Martin
2015-03-27 16:40   ` Jakub Kiciński
2015-03-27 16:40     ` Jakub Kiciński
2015-03-27 17:42     ` Dave P Martin
2015-03-27 17:42       ` Dave P Martin
2015-03-27 18:10       ` Jakub Kiciński
2015-03-27 18:10         ` Jakub Kiciński
2015-03-30 12:28         ` Dave Martin
2015-03-30 12:28           ` Dave Martin
2015-03-30 14:26           ` Jakub Kiciński
2015-03-30 14:26             ` Jakub Kiciński
2015-03-30 16:07             ` Dave Martin
2015-03-30 16:07               ` Dave Martin
2015-03-30 14:28   ` Jakub Kiciński [this message]
2015-03-30 14:28     ` Jakub Kiciński
2015-03-30 16:09     ` Dave Martin
2015-03-30 16:09       ` Dave Martin

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