Re: [PATCH] mmc: block: Add new ioctl to send multi commands

From	Grant Grundler <grundler@google.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] mmc: block: Add new ioctl to send multi commands
Date	2015-09-10 22:30 +0200
Message-ID	<q7gDM-3PH-9@gated-at.bofh.it> (permalink)
References	(2 earlier) <q6QJk-ho-13@gated-at.bofh.it> <q6Uae-5ii-9@gated-at.bofh.it> <q75oZ-4nU-15@gated-at.bofh.it> <q7dFU-7WH-15@gated-at.bofh.it> <q7eLE-11U-17@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Thu, Sep 10, 2015 at 11:20 AM, Jon Hunter <jonathanh@nvidia.com> wrote:
>
> On 10/09/15 18:10, Grant Grundler wrote:
...
>>>>>> struct mmc_ioc_multi_cmd {
>>>>>>     __u64 num_of_cmds;
>>>>>>     struct mmc_ioc_cmd cmds[0];
>>>>>> };
>>
>> I think this would work just as well. But doesn't "pointer to an
>> array" require 32-bit ioctl compat handling?
>> We were trying to avoid a 32-bit user space compatibility handler.
>
> I think that this is fine as it is a zero length array [0] and not a
> pointer.

Doh, yes. Thanks for correcting. I knew this was a gcc special but
forgot it's not actually allocating any space.

cheers,
grant

>
> Cheers
> Jon
>
> [0] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
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[PATCH] mmc: block: Add new ioctl to send multi commands Jon Hunter <jonathanh@nvidia.com> - 2015-09-09 17:10 +0200
  Re: [PATCH] mmc: block: Add new ioctl to send multi commands Arnd Bergmann <arnd@arndb.de> - 2015-09-09 18:00 +0200
    Re: [PATCH] mmc: block: Add new ioctl to send multi commands Jon Hunter <jonathanh@nvidia.com> - 2015-09-09 18:50 +0200
      Re: [PATCH] mmc: block: Add new ioctl to send multi commands Arnd Bergmann <arnd@arndb.de> - 2015-09-09 22:30 +0200
        Re: [PATCH] mmc: block: Add new ioctl to send multi commands Jon Hunter <jonathanh@nvidia.com> - 2015-09-10 10:30 +0200
          Re: [PATCH] mmc: block: Add new ioctl to send multi commands Arnd Bergmann <arnd@arndb.de> - 2015-09-10 10:40 +0200
          Re: [PATCH] mmc: block: Add new ioctl to send multi commands Grant Grundler <grundler@google.com> - 2015-09-10 19:20 +0200
            Re: [PATCH] mmc: block: Add new ioctl to send multi commands Jon Hunter <jonathanh@nvidia.com> - 2015-09-10 20:30 +0200
              Re: [PATCH] mmc: block: Add new ioctl to send multi commands Grant Grundler <grundler@google.com> - 2015-09-10 22:30 +0200

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