Date: Tue, 28 Aug 2012 14:19:10 +0000 (UTC) From: Warner Losh <imp@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r239780 - head/sys/arm/at91 Message-ID: <201208281419.q7SEJAc6080320@svn.freebsd.org>
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Author: imp Date: Tue Aug 28 14:19:10 2012 New Revision: 239780 URL: http://svn.freebsd.org/changeset/base/239780 Log: Clip the upper end to 31MHz for slow clock speeds. On faster machines, we wind up with a 66MHz clock, which is too fast. Modified: head/sys/arm/at91/at91_mci.c Modified: head/sys/arm/at91/at91_mci.c ============================================================================== --- head/sys/arm/at91/at91_mci.c Tue Aug 28 13:35:37 2012 (r239779) +++ head/sys/arm/at91/at91_mci.c Tue Aug 28 14:19:10 2012 (r239780) @@ -557,10 +557,10 @@ at91_mci_update_ios(device_t brdev, devi * Calculate our closest available clock speed that doesn't exceed the * requested speed. * - * If the master clock is greater than 50MHz and the requested bus - * speed is 25mhz and the use_30mhz flag is on, set clkdiv to zero to - * get a master_clock / 2 (25-30MHz) MMC/SD clock rather than settle for - * the next lower click (12-15MHz). See comments near the top of the + * If the master clock is 50MHz-62MHz and the requested bus speed is + * 25mhz and the use_30mhz flag is on, set clkdiv to zero to get a + * master_clock / 2 (25-31MHz) MMC/SD clock rather than settle for the + * next lower click (12.5-15.5MHz). See comments near the top of the * file for more info. * * Whatever we come up with, store it back into ios->clock so that the @@ -572,7 +572,8 @@ at91_mci_update_ios(device_t brdev, devi } else { WR4(sc, MCI_CR, MCI_CR_MCIEN|MCI_CR_PWSEN); if (sc->use_30mhz && ios->clock == 25000000 && - at91_master_clock > 50000000) + at91_master_clock > 50000000 && + at91_master_clock < 62000000) clkdiv = 0; else if ((at91_master_clock % (ios->clock * 2)) == 0) clkdiv = ((at91_master_clock / ios->clock) / 2) - 1;
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