this case is already catched in at91_do_twi_transfer():

Sorry, I did not found this code in your patch.
(http://www.mail-archive.com/linux-i2c at vger.kernel.org/msg06556.html):

+       if (is_read) {
+               if (!dev->buf_len)
+                       at91_twi_write(dev, AT91_TWI_CR,
+                                      AT91_TWI_START | AT91_TWI_STOP);
+               else
+                       at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_START);
+               at91_twi_write(dev, AT91_TWI_IER,
+                              AT91_TWI_TXCOMP | AT91_TWI_RXRDY);
+       } else {
+               at91_twi_write_next_byte(dev);
+               at91_twi_write(dev, AT91_TWI_IER,
+                              AT91_TWI_TXCOMP | AT91_TWI_TXRDY);
+       }

Is there a more recent version ?

Mit freundlichen Gr??en / Best regards
Carsten Behling

Development Engineer
Garz & Fricke GmbH
Tempowerkring 2, 21079 Hamburg - Germany
Amtsgericht Hamburg HRB 60514
Gesch?ftsf?hrer: Manfred Garz, Matthias Fricke
Phone: +49 (0) 40 791 899 - 56
Fax:    +49 40 / 791 899 - 39
www.garz-fricke.com 

 


-----Urspr?ngliche Nachricht-----
Von: Voss, Nikolaus [mailto:N.Voss at weinmann.de] 
Gesendet: Dienstag, 22. November 2011 17:26
An: Carsten Behling
Cc: 'linux-i2c at vger.kernel.org'; 'linux-arm-kernel at lists.infradead.org'; 'linux-kernel at vger.kernel.org'
Betreff: RE: [PATCH v5 3/4] drivers/i2c/busses/i2c-at91.c: add new driver

Hi,

Carsten Behling wrote on 2011-11-22:

+static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
+{
+       *dev->buf = at91_twi_read(dev, AT91_TWI_RHR) & 0xff;
+
+       /* send stop if second but last byte has been read */
+       if (--dev->buf_len == 1)
+               at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);



If dev->buf_len =1 at the beginning of a read transfer, a stop condition will
never be send.

this case is already catched in at91_do_twi_transfer():

+       if (dev->msg->flags & I2C_M_RD) {
+               unsigned start_flags = AT91_TWI_START;
+
+               /* if only one byte is to be read, immediately stop transfer */
+               if (dev->buf_len <= 1 && !(dev->msg->flags & I2C_M_RECV_LEN))
+                       start_flags |= AT91_TWI_STOP;
+               at91_twi_write(dev, AT91_TWI_CR, start_flags);

Thanks for reviewing,
Niko