From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tero Kristo Subject: Re: [PATCH RFC 0/2] mach-omap2: handle autoidle denial Date: Thu, 4 Oct 2018 17:42:25 +0300 Message-ID: <013b01a1-2593-bdc0-dd9a-e5a114388067@ti.com> References: <20181004055147.23048-1-andreas@kemnade.info> <20181004142558.GB5662@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181004142558.GB5662@atomide.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Tony Lindgren , Andreas Kemnade Cc: mturquette@baylibre.com, sboyd@kernel.org, linux-omap@vger.kernel.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, paul@pwsan.com, letux-kernel@openphoenux.org List-Id: linux-omap@vger.kernel.org On 04/10/18 17:25, Tony Lindgren wrote: > * Andreas Kemnade [181004 05:56]: >> On the gta04 with a dm3730 omap_hdq does not work properly when the >> device enters lower power states. Idling uart1 and 2 is enough >> to show up that problem, if there are no other things enabled. >> Further research reveals that hdq iclk must not be turned off during >> transfers, also according to the TRM. That fact is also correctly described >> in the flags but the code to handle that is incomplete. >> >> Since the order is first disable all autoidles, then disable selected >> and then enable all, we need to either change that order or add >> a usecount. Since it is done only in init, we could think about changing >> order. > > These patches look OK to me, assuming Tero will review them more > closely. There is no locking whatsoever in the autoidle counting atm, that must be fixed otherwise you get races. > It seems we should just provide a generic interface for > clk_allow_autoidle() and clk_deny_autoidle()? Otherwise we'll > be forever stuck with pdata callbacks it seems. The TI clock driver is actually providing these APIs, so that should be fine. I don't think there is any use / need for pdata callbacks atm, it just happens hwmod core is calling these at the moment which might have confused you. -Tero -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki