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From: b-cousson@ti•com (Cousson, Benoit)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/2] ARM: OMAP4: DSS hwmods: Add OCPIF_SWSUP_IDLE to all DSS L3 slave interfaces
Date: Fri, 13 Apr 2012 10:43:22 +0200	[thread overview]
Message-ID: <4F87E72A.2050104@ti.com> (raw)
In-Reply-To: <1334304116-18872-3-git-send-email-archit@ti.com>

On 4/13/2012 10:01 AM, Archit Taneja wrote:
> The clock for all DSS L3 slave interfaces had been recently changed to
> "dss_fck" from "l3_div_ck". "dss_fck" is an optional clock in DSS clock domain
> which can't autoidle when enabled.
>
> Add OCPIF_SWSUP_IDLE flag to all the L3 slave interfaces used by DSS hwmods so
> that clock is explicitly enabled and disabled by software. Without this,
> "dss_fck" would be left as enabled and the OMAP4 device won't idle even when
> DSS is not in use.

Yeah, that was done on purpose with Tomi knowning well that limitation.

The issue was mainly due to the lack of proper parent / child 
relationship between the DSS (the whole subsystem) and the DSS children 
at that time.

I think that Tomi posted a series to fix that for 3.4. So if we ensure 
that every DSS IPs are children of the DSS, then pm_runtime will always 
ensure that the DSS will be enabled each time a submodule is used.

So the right fix is to put back the proper iclk (l3_div) to the DSS 
instead of the dss_fck.

The current OMAP4 DSS clock setup is clearly a hack that should be fixed.

Regards,
Benoit

  reply	other threads:[~2012-04-13  8:43 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-13  8:01 [PATCH 0/2] ARM: OMAP2PLUS: DSS hwmod fixes Archit Taneja
2012-04-13  8:01 ` [PATCH 1/2] ARM: OMAP2/3: VENC hwmods: Remove OCPIF_SWSUP_IDLE flag from VENC slave interface Archit Taneja
2012-04-13 11:20   ` Paul Walmsley
2012-04-13 11:24     ` Paul Walmsley
2012-04-13 11:37       ` Archit Taneja
2012-04-13  8:01 ` [PATCH 2/2] ARM: OMAP4: DSS hwmods: Add OCPIF_SWSUP_IDLE to all DSS L3 slave interfaces Archit Taneja
2012-04-13  8:43   ` Cousson, Benoit [this message]
2012-04-13  8:51     ` Archit Taneja
2012-05-04  6:39       ` Paul Walmsley
2012-05-04  7:03         ` Archit Taneja
2012-05-04  8:51           ` Tomi Valkeinen

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