Re: [PATCH 00/13] Add IPU & DSP remoteprocs on OMAP4 and OMAP5

From: Suman Anna <s-anna@ti.com>
To: Tony Lindgren <tony@atomide.com>
Cc: <linux-omap@vger.kernel.org>, <devicetree@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	Tero Kristo <t-kristo@ti.com>
Subject: Re: [PATCH 00/13] Add IPU & DSP remoteprocs on OMAP4 and OMAP5
Date: Fri, 10 Jul 2020 12:17:51 -0500	[thread overview]
Message-ID: <41bd2bb4-06fe-5f70-22cf-ce9cedc8bbc3@ti.com> (raw)
In-Reply-To: <20200710165814.GF5849@atomide.com>

On 7/10/20 11:58 AM, Tony Lindgren wrote:
> Hi,
> 
> * Suman Anna <s-anna@ti.com> [200709 16:20]:
>> Hi Tony,
>>
>> The following series contains all the necessary DT pieces to boot the
>> IPU and DSP remote processors on OMAP4 and OMAP5 SoCs. They are
>> enabled specifically on the TI OMAP4 PandaBoard and OMAP5 uEVM boards.
>> This is the last DT piece that now completes the support for IPUs and
>> DSPs on all OMAP4+ SoCs, similar patches were merged for 5.8 covering
>> the DRA7xx/AM57xx SoCs. Appreciate it if you can pick up the series for
>> 5.9 if it isn't too late.
> 
> Great and good to hear things are working with only dts changes now :)
> Yes let's try to get these merged.

Thanks.

> 
>> There is one issue that I have run into while testing this series on
>> the latest kernel. I am seeing a l3_noc error for OMAP4 DSP when it
>> attempts to auto-suspend or stop after it is booted. The issue is a
>> L4CFG read error that happens in the sysc_disable_module() function
>> in ti-sysc code.
>>
>> I do not have any issues on my downstream 5.4 based SDK kernel. I have
>> root-caused this to the OMAP4 voltage controller patches you added for
>> 5.5 kernel through your omap-for-v5.5/pm branch, specifically the
>> commit 4873843718f9 ("ARM: OMAP2+: Initialize voltage controller for omap4").
>> The VOLTCTRL register value is 0x300 before that patch, and modifying
>> this register either through  omap4_vc_init_pmic_signaling() or
>> omap4_vc_set_pmic_signaling() will trigger this. A debug print in
>> sysc_disable_module() also seems to help.
> 
> Hmm interesting, not sure how the VOLTCTRL register affects this.
> 
> I wonder the following commit in v5.8-rc3 might help with this though:
> 
> 5ce8aee81be6 ("bus: ti-sysc: Flush posted write on enable and disable")
> 

I had already tested on v5.8-rc4 when I posted the patches, so this 
patch doesn't help. OMAP5 DSP is fine, because Think it has to do with 
this automated

So, I am looking at the TRM, and the three 
VDD_{IVA,MPU,CORE}_I2C_DISABLE bits in VOLTCTRL are marked debug-purpose 
only, so I don't think we should be setting those to begin with. Any 
reason why you want to set those? Anyway, these bits were not an issue, 
I have specifically tried that already.

regards
Suman

> I was seeing that occasionally with mcspi, but never had anything
> reproducable.
> 
> Regards,
> 
> Tony
> 