Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <bab4d845-330e-c7f0-5dac-a96caa93a39e@linaro.org>
Date:   Wed, 29 Jun 2022 20:25:57 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.10.0
Subject: Re: [PATCH 5/7] memory: renesas-rpc-if: Move resource acquisition to
 .probe()
Content-Language: en-US
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     Vignesh Raghavendra <vigneshr@ti.com>,
        Sergey Shtylyov <s.shtylyov@omp.ru>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Mark Brown <broonie@kernel.org>,
        MTD Maling List <linux-mtd@lists.infradead.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        linux-spi <linux-spi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <cover.1656341824.git.geert+renesas@glider.be>
 <2fd9b9e3f60fe555d9dcad499c90e3ec869aa96e.1656341824.git.geert+renesas@glider.be>
 <c65d6a94-b5c2-e2e4-6fdb-b7982d291e01@linaro.org>
 <CAMuHMdW=s42sfFwimizTsNjyKue+W9NasTOG0jgjkgkoKv3wfw@mail.gmail.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <CAMuHMdW=s42sfFwimizTsNjyKue+W9NasTOG0jgjkgkoKv3wfw@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 29/06/2022 19:55, Geert Uytterhoeven wrote:
> Hi Krzysztof,
> 
> On Wed, Jun 29, 2022 at 7:44 PM Krzysztof Kozlowski
> <krzysztof.kozlowski@linaro.org> wrote:
>> On 27/06/2022 17:31, Geert Uytterhoeven wrote:
>>> While the acquired resources are tied to the lifetime of the RPC-IF core
>>> device (through the use of managed resource functions), the actual
>>> resource acquisition is triggered from the HyperBus and SPI child
>>> drivers.  Due to this mismatch, unbinding and rebinding the child
>>> drivers manually fails with -EBUSY:
>>>
>>>     # echo rpc-if-hyperflash > /sys/bus/platform/drivers/rpc-if-hyperflash/unbind
>>>     # echo rpc-if-hyperflash > /sys/bus/platform/drivers/rpc-if-hyperflash/bind
>>>     rpc-if ee200000.spi: can't request region for resource [mem 0xee200000-0xee2001ff]
>>>     rpc-if-hyperflash: probe of rpc-if-hyperflash failed with error -16
>>>
>>> Fix this by moving all resource acquisition to the core driver's probe
>>> routine.
>>>
>>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
>>
>> This looks like a fix, so how about putting it as first in the series,
>> so backporting is easy/automatic?
> 
> Unfortunately that is not as simple as it sounds, as this really
> depends on patch 4.

You sure? Except rebasing I don't see that. rpcif_sw_init() received the
rpcif so it had access to all fields.


> I agree patches 1-3 could be moved later, if you think it is worthwhile.

This would not be enough, it has to be first patch to be backportable.

Best regards,
Krzysztof