Date: Wed, 10 Jan 2007 21:49:23 -0700 (MST) From: "M. Warner Losh" <imp@bsdimp.com> To: ticso@cicely.de, ticso@cicely12.cicely.de Cc: perforce@freebsd.org Subject: Re: PERFORCE change 112700 for review Message-ID: <20070110.214923.-311943684.imp@bsdimp.com> In-Reply-To: <20070110091917.GF80390@cicely12.cicely.de> References: <200701100656.l0A6uuTm065800@repoman.freebsd.org> <20070110091917.GF80390@cicely12.cicely.de>
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In message: <20070110091917.GF80390@cicely12.cicely.de> Bernd Walter <ticso@cicely12.cicely.de> writes: : On Wed, Jan 10, 2007 at 06:56:56AM +0000, Warner Losh wrote: : > http://perforce.freebsd.org/chv.cgi?CH=112700 : > : > Change 112700 by imp@imp_lighthouse on 2007/01/10 06:56:33 : > : > MF FreeBSD-tsc-6: slow down spi bus enough to make the dataflash : > parts reliable on read. MCK / 2 is too fast. I think MCK / 4 : > would work too, but MCK / 20 was rock solid. : > : > I think this works in the boot loader because we're running with : > the caches off, slowing things down, but I am actually a bit : > baffled. Maybe I just have a bad board... : : Mmm - you have a 'D' type flash, which allows 33MHz in low frequency : mode. : My 'C' type allows 33MHz as well. : So in theory MCK/2 (30MHz) should work. : Older 'B' type max out at 20MHz. : I've just used flash access in the bootloader however. Hmmm, MCK is 60MHz? I thought it was 200MHz.... Warner : > Affected files ... : > : > .. //depot/projects/arm/src/sys/arm/at91/at91_spi.c#16 edit : > : > Differences ... : > : > ==== //depot/projects/arm/src/sys/arm/at91/at91_spi.c#16 (text+ko) ==== : > : > @@ -115,7 +115,7 @@ : > WR4(sc, SPI_MR, (0xf << 24) | SPI_MR_MSTR | SPI_MR_MODFDIS | : > (0xE << 16)); : > : > - WR4(sc, SPI_CSR0, SPI_CSR_CPOL | (4 << 16) | (2 << 8)); : > + WR4(sc, SPI_CSR0, SPI_CSR_CPOL | (4 << 16) | (20 << 8)); : > WR4(sc, SPI_CR, SPI_CR_SPIEN); : > : > WR4(sc, PDC_PTCR, PDC_PTCR_TXTDIS); : : -- : B.Walter http://www.bwct.de http://www.fizon.de : bernd@bwct.de info@bwct.de support@fizon.de :
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