Date: Fri, 18 Dec 2015 01:25:30 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r292419 - head/sys/arm/freescale/imx Message-ID: <201512180125.tBI1PUnZ076695@repo.freebsd.org>
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Author: ian Date: Fri Dec 18 01:25:30 2015 New Revision: 292419 URL: https://svnweb.freebsd.org/changeset/base/292419 Log: Fix the clock divisor calc for imx6 sdcard bus speed. I don't know what alternate universe I was inhabiting when I wrote it originally, but apparently the basic workings of mathematics were different than in this universe. I also can't explain how it ever worked, except "by accident", because completely bogus values were being written into the divisor register. Modified: head/sys/arm/freescale/imx/imx_sdhci.c Modified: head/sys/arm/freescale/imx/imx_sdhci.c ============================================================================== --- head/sys/arm/freescale/imx/imx_sdhci.c Fri Dec 18 01:03:34 2015 (r292418) +++ head/sys/arm/freescale/imx/imx_sdhci.c Fri Dec 18 01:25:30 2015 (r292419) @@ -522,12 +522,19 @@ imx_sdhc_set_clock(struct imx_sdhci_soft else freq = sc->baseclk_hz / (2 * divisor); - for (prescale = 2; prescale < freq / prescale / 16;) + for (prescale = 2; freq < sc->baseclk_hz / (prescale * 16);) prescale <<= 1; - for (divisor = 1; freq < freq / prescale / divisor;) + for (divisor = 1; freq < sc->baseclk_hz / (prescale * divisor);) ++divisor; +#ifdef DEBUG + device_printf(sc->dev, + "desired SD freq: %d, actual: %d; base %d prescale %d divisor %d\n", + freq, sc->baseclk_hz / (prescale * divisor), sc->baseclk_hz, + prescale, divisor); +#endif + prescale >>= 1; divisor -= 1;
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