Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: dma_mask limited to 32-bits with OF platform device
To:     Rob Herring <robh+dt@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>
CC:     Christoph Hellwig <hch@lst.de>,
        =?UTF-8?Q?P=c3=a9ter_Ujfalusi?= <peter.ujfalusi@ti.com>,
        Murali Karicheri <m-karicheri2@ti.com>,
        "Nori, Sekhar" <nsekhar@ti.com>, "Anna, Suman" <s-anna@ti.com>,
        Stefan Wahren <stefan.wahren@i2se.com>,
        =?UTF-8?Q?Andreas_F=c3=a4rber?= <afaerber@suse.de>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Nishanth Menon <nm@ti.com>,
        "hdegoede@redhat.com" <hdegoede@redhat.com>,
        Vignesh Raghavendra <vigneshr@ti.com>
References: <c1c75923-3094-d3fc-fe8e-ee44f17b1a0a@ti.com>
 <3a91f306-f544-a63c-dfe2-7eae7b32bcca@arm.com>
 <56314192-f3c6-70c5-6b9a-3d580311c326@ti.com>
 <9bd83815-6f54-2efb-9398-42064f73ab1c@arm.com>
 <20200217132133.GA27134@lst.de> <b3c56884-128e-a7e1-2e09-0e8de3c3512d@ti.com>
 <CAL_JsqLxECRKWG3SoORADtZ-gVbqCHyx9mhGzrCPO+X=--w8AQ@mail.gmail.com>
 <15d0ac5f-4919-5852-cd95-93c24d8bdbb9@ti.com>
 <827fa19d-1990-16bc-33f5-fc82ac0d4a8a@arm.com>
 <3d8ea578-2ecb-1126-3bf0-2dc695687245@ti.com>
 <e898cf0a-6f52-8550-c73e-b78bc413bcc7@ti.com>
 <98db4748-63cb-79db-50c3-a6a37d624eaa@arm.com>
 <CAL_Jsq+zx5qkv1DZdj1p2HHz5siYZwv6WGLe1F7xw9b019UWbQ@mail.gmail.com>
From:   Roger Quadros <rogerq@ti.com>
Message-ID: <c753a232-403d-6ed2-89fd-09476c887391@ti.com>
Date:   Wed, 4 Mar 2020 10:28:28 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.4.1
MIME-Version: 1.0
In-Reply-To: <CAL_Jsq+zx5qkv1DZdj1p2HHz5siYZwv6WGLe1F7xw9b019UWbQ@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi,

On 03/03/2020 21:26, Rob Herring wrote:
> On Tue, Mar 3, 2020 at 8:06 AM Robin Murphy <robin.murphy@arm.com> wrote:
>>
>> On 03/03/2020 8:27 am, Roger Quadros wrote:
>> [...]
>>>> With the patch (in the end). dev->bus_dma_limit is still set to 0 and
>>>> so is not being used.
>>>>
>>>> from of_dma_configure()
>>>>           ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
>>>> ...
>>>>           /* ...but only set bus limit if we found valid dma-ranges
>>>> earlier */
>>>>           if (!ret)
>>>>                   dev->bus_dma_limit = end;
>>>>
>>>> There is no other place bus_dma_limit is set. Looks like every device
>>>> should inherit that
>>>> from it's parent right?
>>>
>>> Any ideas how to expect this to work?
>>
>> Is of_dma_get_range() actually succeeding, or is it tripping up on some
>> aspect of the DT (in which case there should be errors in the log)?
>>

of_dma_get_range() was failing but no errors in the log.

>> Looking again at the fragment below, are you sure it's correct? It
>> appears to me like it might actually be defining a 1-byte-long DMA
>> range, which indeed I wouldn't really expect to work.
> 
> Indeed, though it took me a minute to see why.
> 
>>
>> Robin.
>>
>>>>
>>>> diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
>>>> index 64a0f90f5b52..5418c31d4da7 100644
>>>> --- a/arch/arm/boot/dts/dra7.dtsi
>>>> +++ b/arch/arm/boot/dts/dra7.dtsi
>>>> @@ -680,15 +680,22 @@
>>>>            };
>>>>
>>>>            /* OCP2SCP3 */
>>>> -        sata: sata@4a141100 {
>>>> -            compatible = "snps,dwc-ahci";
>>>> -            reg = <0x4a140000 0x1100>, <0x4a141100 0x7>;
> 
> Based on this, the parent address size is 1 cell...
> 
>>>> -            interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
>>>> -            phys = <&sata_phy>;
>>>> -            phy-names = "sata-phy";
>>>> -            clocks = <&l3init_clkctrl DRA7_L3INIT_SATA_CLKCTRL 8>;
>>>> -            ti,hwmods = "sata";
>>>> -            ports-implemented = <0x1>;
>>>> +        sata_aux_bus {
>>>> +            #address-cells = <2>;
>>>> +            #size-cells = <2>;
>>>> +            compatible = "simple-bus";
>>>> +            ranges = <0x0 0x0 0x4a140000 0x0 0x1200>;
>>>> +            dma-ranges = <0x0 0x0 0x0 0x0 0x1 0x00000000>;
> 
> So this is:
> child addr: 0x0 0x0
> parent addr: 0x0
> size: 0x0 0x1

Good catch.
So I fixed it to

	dma-ranges = <0x0 0x0 0x0 0x1 0x00000000>;

And now it works :).
Thanks!

> 
> The last cell is just ignored I guess if you aren't seeing any errors.
> We check this in dtc for ranges, but not dma-ranges. So I'm fixing
> that.

Great!

> 
>>>> +            sata: sata@4a141100 {
>>>> +                compatible = "snps,dwc-ahci";
>>>> +                reg = <0x0 0x0 0x0 0x1100>, <0x0 0x1100 0x0 0x7>;
>>>> +                interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
>>>> +                phys = <&sata_phy>;
>>>> +                phy-names = "sata-phy";
>>>> +                clocks = <&l3init_clkctrl DRA7_L3INIT_SATA_CLKCTRL 8>;
>>>> +                ti,hwmods = "sata";
>>>> +                ports-implemented = <0x1>;
>>>> +            };
>>>>            };
>>>>
>>>>            /* OCP2SCP1 */
>>>>
>>>

-- 
cheers,
-roger
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki