[PATCH v2] SPI SD-Card: setup valid CRC-7 for STOP_TRANSMISSION command.

Pavel Pisa ppisa4lists at pikron.com
Tue Oct 8 08:40:29 UTC 2013


From: Pavel Pisa <ppisa at pikron.com>

STOP_TRANSMISSION command is used to finish READ_MULTIPLE_BLOCK
command and its format is regular command format.
It requires valid CRC-7 to have effect at least on
same cards types else it is ignored and attempt
to issue next READ or WRITE commands results in
illegal command condition (0x04) preceded by strange
(0x3f) for tested card.

Signed-off-by: Pavel Pisa <ppisa at pikron.com>
---
 c/src/libchip/i2c/spi-sd-card.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/c/src/libchip/i2c/spi-sd-card.c b/c/src/libchip/i2c/spi-sd-card.c
index ade3860..03d4924 100644
--- a/c/src/libchip/i2c/spi-sd-card.c
+++ b/c/src/libchip/i2c/spi-sd-card.c
@@ -501,8 +501,13 @@ static int sd_card_send_register_command( sd_card_driver_entry *e, uint32_t comm
 static int sd_card_stop_multiple_block_read( sd_card_driver_entry *e)
 {
 	int rv = 0;
+	uint8_t crc7;
 
 	SD_CARD_COMMAND_SET_COMMAND( e->command, SD_CARD_CMD_STOP_TRANSMISSION);
+	SD_CARD_COMMAND_SET_ARGUMENT( e->command, 0);
+	/*crc7 = sd_card_compute_crc7( e->command + 1, 5);*/
+	crc7 = 0x30;	/* Help compiler - command and argument are constants */
+	SD_CARD_COMMAND_SET_CRC7( e->command, crc7);
 	rv = rtems_libi2c_write_bytes( e->bus, e->command, SD_CARD_COMMAND_SIZE);
 	RTEMS_CHECK_RV( rv, "Write stop transfer token");
 
-- 
1.7.10.4




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