From: Yi Li Date: Tue, 7 Apr 2009 02:00:44 +0000 (-0700) Subject: Blackfin SPI Driver: fix bug - spi controller driver does not assert/deassert CS... X-Git-Tag: v2.6.30-rc1~111 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2cf3683472f043e6748c48228df6d8a35a47ecc2;p=pandora-kernel.git Blackfin SPI Driver: fix bug - spi controller driver does not assert/deassert CS correctly This bug can be observed when two SPI devices are sharing the spi bus: One device is set as SPI CS 7, another one is using SPI CS 4. In spi_bfin5xx.c: cs_active(), cs_deactive() are used to control SPI_FLG register. From the debug bellow: cs_active: flag: 0x7f91, chip->flag: 0x7f80, cs: 7 cs_active: flag: 0xef91, chip->flag: 0xef10, cs: 4 When device A (cs_7) activate CS 7, SPI_FLG is set as 0x7f91 (however, SPI_FLG should be set as 0x7f80, or 0x6f91 if in broadcast mode). Due to some HW bug (very possibly), if SPI_FLG is set as 0x7f91, SPISSEL7 is asserted, however SPISSEL4 will be asserted too (I can see this using the scope). This is unreasonable according to HRM. Signed-off-by: Yi Li Signed-off-by: Bryan Wu Acked-by: David Brownell Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed