linux-kernel - Re: Weird/Unneeded call to msleep in exynos_mipi_dsi_wr_data in exynos_mipi_dsi

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Date:	Thu, 18 Dec 2014 16:05:01 +0200
From:	Tomi Valkeinen <tomi.valkeinen@...com>
To:	nick <xerofoify@...il.com>
CC:	Lucas Stach <l.stach@...gutronix.de>,
	Krzysztof Kozłowski 
	<k.kozlowski@...sung.com>, <inki.dae@...sung.com>,
	<linux-fbdev@...r.kernel.org>, <linux-samsung-soc@...r.kernel.org>,
	<dh09.lee@...sung.com>, <linux-kernel@...r.kernel.org>,
	<kyungmin.park@...sung.com>, <kgene@...nel.org>,
	<plagnioj@...osoft.com>, <linux-arm-kernel@...ts.infradead.org>
Subject: Re: Weird/Unneeded call to msleep in exynos_mipi_dsi_wr_data in exynos_mipi_dsi_common.c

On 18/12/14 15:48, nick wrote:
> Lucas,
> That's fair do you known of anyone who does have the hardware so we can test my patch. If you do then we can get this fixed rather
> easily.
> Cheers Nick 
> 
> On 2014-12-18 08:39 AM, Lucas Stach wrote:
>> Am Donnerstag, den 18.12.2014, 08:35 -0500 schrieb nick:
>>> Krzysztof,
>>> If we look at the code for this function, it already is handling the data correctly. In addition  the locks 
>>> seem to be better protection then msleep. Further more is no reason for this delay as we are neither resetting 
>>> the hardware or waiting for the hardware here so why is it needed? I don't have Exynos based hardware lying
>>> around through to test it.
>>
>> If you can't test it, don't touch it. It's that simple.

There seems to be multiple msleep(20)s in exynos_mipi_dsi_common.c, a
few with /* FIXME */ and a few without any comments. Looks like bad (but
relatively harmless) code to me, but as Lucas said, if you can't test
it, don't touch it.

 Tomi



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