[PATCH] ARM: imx: add cpuidle support for i.mx6ul
From: Yongcai Huang <hidden>
Date: 2016-08-29 10:07:05
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Best Regards! Anson Huang
-----Original Message----- From: Shawn Guo [mailto:shawnguo at kernel.org] Sent: 2016-08-29 3:24 PM To: Lucas Stach <l.stach@pengutronix.de>; Yongcai Huang [off-list ref] Cc: linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org; Fabio Estevam [off-list ref]; linux at armlinux.org.uk; kernel at pengutronix.de Subject: Re: [PATCH] ARM: imx: add cpuidle support for i.mx6ul On Wed, Aug 24, 2016 at 12:04:50PM +0200, Lucas Stach wrote:quoted
Personally I would just remove the condition, but if you are concerned about the double L1 flush overhead (I wouldn't worry about this, it should be negligible) you should really make this conditional on an architected L2 being present. Making it conditional on the outer cache being absent is confusing.Anson, Is there any concern or problem if we follow Lucas' suggestion to unconditionally calls flush_cache_all() here? Shawn
Because this code is in idle thread, my original aim is to make the latency as small as possible, but since the double L1 flush here should finish very quick at this stage and compare to hardware ARM core power down/up latency, it should be negligible as Lucas mentioned, yes, I agree to remove condition check here and just call L1 flush again to avoid any confusion. Will send out a V2 patch later, thanks. Anson.