>-----Original Message----- >From: Mike Frysinger [mailto:[email protected]] >Sent: Thursday, November 26, 2009 6:02 PM >To: Cai, Cliff >Cc: [email protected]; >[email protected] >Subject: Re: [Linux-kernel-commits] [7883] >trunk/drivers/spi/bfin_sport_spi.c: bug[#5722] use the new >gpio cs scheme > >On Thu, Nov 26, 2009 at 01:02, Cai, Cliff wrote: >>From: Mike Frysinger [mailto:[email protected]] >>>On Wed, Nov 25, 2009 at 22:06, <[email protected]> wrote: >>>> Revision 7883 Author cliff Date 2009-11-25 22:06:52 -0500 >>>(Wed, 25 Nov >>>> 2009) >>>> >>>> Log Message >>>> >>>> bug[#5722]use the new gpio cs scheme >>>> >>>> trunk/drivers/spi/bfin_sport_spi.c >>>> >>>> static void bfin_sport_spi_cs_active(struct master_data >*drv_data, >>>> struct slave_data *chip) { >>>> - gpio_direction_output(chip->cs_gpio, 0); >>>> + if (chip->chip_select_num > MAX_CTRL_CS) >>>> + gpio_direction_output(chip->cs_gpio, 0); >>>> } >>> >>>these MAX_CTRL_CS checks make no sense at all. the CS with the >>>SPORT/SPI bus can only ever be GPIOs. >> >> Not really,the sport can provide cs by itself. > >except that MAX_CTRL_CS is specific to the Blackfin SPI >controller -- the SPORT does not support 7 different >"internal" cs's. the driver also doesnt explain how exactly >"the sport is in charge of it". >before your commit, a GPIO CS was always used. after your >commit, the GPIO CS is sometimes used, but otherwise, no >"internal" cs changes are apparent. >-mike
If we don't use GPIO as CS, then SPORT can provide cs-change-per-word kind of CS. And we can't control it.I will add the comments in the driver. Cliff _______________________________________________ Linux-kernel-commits mailing list [email protected] https://blackfin.uclinux.org/mailman/listinfo/linux-kernel-commits
