From mboxrd@z Thu Jan 1 00:00:00 1970 From: b-cousson@ti.com (Cousson, Benoit) Date: Fri, 8 Jun 2012 15:13:48 +0200 Subject: [PATCH 04/11] ARM: OMAP2+: usb_host_fs: add custom reset for usb_host_fs (fsusb) In-Reply-To: References: <20120607060901.25532.68354.stgit@dusk> <20120607061308.25532.19767.stgit@dusk> <20120607073112.GX12766@atomide.com> <20120607075158.GZ12766@atomide.com> <20120607075541.GF16342@arwen.pp.htv.fi> <4FD0602B.9070704@ti.com> <4FD09EFA.20304@ti.com> Message-ID: <4FD1FA8C.1080600@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 6/8/2012 3:11 AM, Paul Walmsley wrote: > On Thu, 7 Jun 2012, Cousson, Benoit wrote: > >> Indeed, what I did not mention is that potentially the whole device init >> should be done ondemand as well. Meaning the whole hwmod setup phase should be >> done only when the driver will probe the device. > > That means if no driver exists for an IP block, or if the driver isn't > using PM runtime, the IP block won't be reset. And somehow we still are > missing drivers in mainline. We also still have drivers that aren't yet > PM runtime converted. No the point is still the same as before. You let the drivers do the job if they are there, and then do a pass at very late time during the boot process to handle the ones that were not probed by any driver. At least you will avoid the enable -> reset -> idle -> enable sequence we are doing right now for most of the active drivers when it is not necessary. Regards, Benoit