linux-kernel - Re: [PATCH v2 06/11] mmc: sdhci: xenon: Use sdhci_set_power_and

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 9 Mar 2020 13:55:26 +0200
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Nicolas Saenz Julienne <nsaenzjulienne@...e.de>,
        linux-kernel@...r.kernel.org, Hu Ziji <huziji@...vell.com>
Cc:     phil@...pberrypi.com, linux-mmc@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, f.fainelli@...il.com,
        stefan.wahren@...e.com, bcm-kernel-feedback-list@...adcom.com,
        linux-rpi-kernel@...ts.infradead.org,
        Ulf Hansson <ulf.hansson@...aro.org>
Subject: Re: [PATCH v2 06/11] mmc: sdhci: xenon: Use
 sdhci_set_power_and_voltage()

On 9/03/20 12:53 pm, Nicolas Saenz Julienne wrote:
> On Mon, 2020-03-09 at 09:20 +0200, Adrian Hunter wrote:
>>> -static void xenon_set_power(struct sdhci_host *host, unsigned char mode,
>>> -		unsigned short vdd)
>>> -{
>>> -	struct mmc_host *mmc = host->mmc;
>>> -	u8 pwr = host->pwr;
>>> -
>>> -	sdhci_set_power_noreg(host, mode, vdd);
>>> -
>>> -	if (host->pwr == pwr)
>>> -		return;
>>> -
>>> -	if (host->pwr == 0)
>>> -		vdd = 0;
>>> -
>>> -	if (!IS_ERR(mmc->supply.vmmc))
>>> -		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
>>> -}
>>
>> This code is different.  The commit message should explain why it is
>> equivalent.  Has it been tested?
> 
> Yes, I should've pointed it out. The rationale behind including sdhci-xenon and
> sdhci-pxav3 is based on xenon's original commit message (99c14fc360dbb):
> 
> 	mmc: sdhci-xenon: add set_power callback
> 
> 	Xenon sdh controller requests proper SD bus voltage select
> 	bits programmed even with vmmc power supply. Any reserved
> 	value(100b-000b) programmed in this field will lead to controller
> 	ignore SD bus power bit and keep its value at zero.
> 	Add set_power callback to handle this.
> 
> I can't test it, but it felt to me as the implementation differences are only
> there as different people wrote the code. Ultimately, I'll be happy to drop
> them from the series if you feel it's too much of an assumption, I can see how
> the controllers could react badly to the ordering change. If not I can send a
> v3 with fixed commit messages.

We can wait a bit and see if anyone provides a Tested-by tag, otherwise
safer to drop it.