On Mon, Apr 9, 2012 at 12:09 AM, Heiko Stübner <he...@sntech.de> wrote: > [@jassi: I know that you do not work at this stuff any longer, but I included > you in the list of recipients in the hope that you might be able to give me a > pointer on where to look for the culprit of the problem :-) ] > > > Hi, > > while working on the beginnings of a wireless driver connected via SPI [1], > the s3c64xx-spi-driver produced strange problems while doing MODE_3 (CPOL | > CPHA) transfers: [2] > > [write] spi cur_bpw: 8: 0x00 0x00 0x04 0x00 > [read] spi cur_bpw: 8: 0x00 0x00 0x00 0x00 > [read] spi cur_bpw: 8: 0x00 0x00 0x00 0x00 > (chip_id = 0x0000, chip_rev = 0x00) > mapped channel 24 to 0 > mapped channel 23 to 1 > [write] spi cur_bpw: 8: 0x00 0x00 0x04 0x00 > [read] spi cur_bpw: 8: 0x00 0x00 0x00 0x00 > [read] spi cur_bpw: 8: 0x00 0x00 0x00 0x00 > CIR: 0 > [write] spi cur_bpw: 8: 0x00 0x00 0x04 0x00 > [read] spi cur_bpw: 8: 0x00 0x00 0x00 0x00 > mt592x_spi spi0.0: I/O Error: rx-1 tx-0 res:rx-f tx-p len-4 > CIR: 0 > [write] spi cur_bpw: 8: 0x00 0x00 0x04 0x00 > mt592x_spi spi0.0: I/O Error: rx-0 tx-1 res:rx-p tx-f len-4 > CIR: 0 > [write] spi cur_bpw: 8: 0x00 0x00 0x04 0x00 > mt592x_spi spi0.0: I/O Error: rx-0 tx-1 res:rx-p tx-f len-4 > CIR: 0 > [write] spi cur_bpw: 8: 0x00 0x00 0x04 0x00 > mt592x_spi spi0.0: I/O Error: rx-0 tx-1 res:rx-p tx-f len-4 > CIR: 0 > > where the expected result would be: > > [write] spi cur_bpw: 8: 0x00 0x00 0x04 0x00 > [read] spi cur_bpw: 8: 0x00 0x00 0x00 0x00 > [read] spi cur_bpw: 8: 0x21 0x59 0x91 0x00 > > The pattern of either empty results or read errors also varies with each > invocation, i.e. sometimes all fail or all result in wrong values and so on. > > > In contrast when doing this with the spi-gpio driver, everything works as > expected and I get the expected results. > > Also the device-family I'm working on contains a variant with a Marvell 8686 > wlan chip [= the rest of the system is the same]. Using the spi-s3c64xx with > the libertas driver (MODE_0) works as expected. > > > As I'm not sure where I should look for errors in the driver, I would be glad > to get pointers in the right direction. > You might want to play around tuning the 'fb_delay' and maybe signal strength too.
-j -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
