[OpenBIOS] r497 - dev/mmc/sdhci
svn at openbios.org
svn at openbios.org
Thu Jul 26 08:42:10 CEST 2007
Author: wmb
Date: 2007-07-26 08:42:10 +0200 (Thu, 26 Jul 2007)
New Revision: 497
Modified:
dev/mmc/sdhci/sdhci.fth
Log:
OLPC trac 2371 - SD is flaky in high-speed (50 MHz) mode on B1,
probably as a result of the FPGA-based CaFe chips on B1.
The firmware fix is to check for a B1 system and avoid switching
to 50 MHz card clock thereon.
Modified: dev/mmc/sdhci/sdhci.fth
===================================================================
--- dev/mmc/sdhci/sdhci.fth 2007-07-26 01:14:50 UTC (rev 496)
+++ dev/mmc/sdhci/sdhci.fth 2007-07-26 06:42:10 UTC (rev 497)
@@ -154,7 +154,12 @@
;
: card-clock-50 ( -- )
card-clock-off
- h# 003 h# 2c cw! \ Set divisor to 2^0, leaving internal clock on
+ h# 003 \ division = 2^0, clocks on
+
+ \ OLPC-specific hack: fast clock doesn't work on the FPGA CaFe chip
+ " board-revision" evaluate h# b20 < if drop h# 103 then
+
+ h# 2c cw! \ Set divisor to 2^0, leaving internal clock on
card-clock-on
;
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