Re: [PATCH] i2c: allow building emev2 without slave mode again

From	Wolfram Sang <wsa@the-dreams.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH] i2c: allow building emev2 without slave mode again
Date	2015-12-12 17:30 +0100
Message-ID	<qEVdv-4sK-7@gated-at.bofh.it> (permalink)
References	<qEaRj-7yx-3@gated-at.bofh.it> <qEb10-7RF-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Hi Arnd,

thanks for looking into this, but I don't get your point yet.

> The slave_cb callback function is supposed to set the 'value'
> here,

Only if a master wants to READ from us.

> but it might return an error not assign the pointer,

An error is only returned if a WRITE from a master was not accepted by
the slave backend.

> It might be best to change the callback to return 'void' and not
> allow it to fail.

We need that because in case of an errno, the slave should send NACK to
the master instead of ACK.

> At least the eeprom slave cannot fail anyway, and it is the only
> implementation we have at the moment.

True. But giving a slave the possibility to NACK a write should be
present IMO.

> Alternatively, the  inline could return an error, and both bus
> drivers check for the error before using 'value'.

Hum, it does return an error?

	return client->slave_cb(client, event, val);

You probably mean something else?

Regards,

   Wolfram

Thread

[PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-10 14:20 +0100
  Re: [PATCH] i2c: allow building emev2 without slave mode again Wolfram Sang <wsa@the-dreams.de> - 2015-12-10 14:40 +0100
    Re: [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-10 15:00 +0100
  Re: [PATCH] i2c: allow building emev2 without slave mode again kbuild test robot <lkp@intel.com> - 2015-12-10 16:00 +0100
    Re: [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-10 16:10 +0100
      Re: [PATCH] i2c: allow building emev2 without slave mode again Wolfram Sang <wsa@the-dreams.de> - 2015-12-10 16:20 +0100
      Re: [PATCH] i2c: allow building emev2 without slave mode again Wolfram Sang <wsa@the-dreams.de> - 2015-12-12 17:30 +0100
        Re: [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-12 22:10 +0100
          Re: [PATCH] i2c: allow building emev2 without slave mode again Wolfram Sang <wsa@the-dreams.de> - 2015-12-13 10:20 +0100
            Re: [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-14 13:10 +0100
              Re: [PATCH] i2c: allow building emev2 without slave mode again Wolfram Sang <wsa@the-dreams.de> - 2015-12-14 15:00 +0100
                Re: [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-14 23:30 +0100
                Re: [PATCH] i2c: allow building emev2 without slave mode again Wolfram Sang <wsa@the-dreams.de> - 2015-12-17 13:10 +0100
                Re: [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-17 15:50 +0100
                Re: [PATCH] i2c: allow building emev2 without slave mode again Wolfram Sang <wsa@the-dreams.de> - 2015-12-17 20:50 +0100
                Re: [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann <arnd@arndb.de> - 2015-12-17 21:00 +0100

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