X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fmmc%2Fhost%2Fmmc_spi.c;h=72f8bde4877a790f8d65f95450aae1723e521c84;hb=2d9aaa76288b9a4d6aca5067154ceb09122aacd8;hp=87e211df68ac0dcdaf75c6aab9f4cce9ebad97ab;hpb=fdbc0450df12cc9cb397f3497db4b0cad7c1a8ff;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 87e211df68a..72f8bde4877 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -279,8 +279,11 @@ static int mmc_spi_response_get(struct mmc_spi_host *host,
 		 * so it can always DMA directly into the target buffer.
 		 * It'd probably be better to memcpy() the first chunk and
 		 * avoid extra i/o calls...
+		 *
+		 * Note we check for more than 8 bytes, because in practice,
+		 * some SD cards are slow...
 		 */
-		for (i = 2; i < 9; i++) {
+		for (i = 2; i < 16; i++) {
 			value = mmc_spi_readbytes(host, 1);
 			if (value < 0)
 				goto done;
@@ -609,6 +612,7 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
 	struct spi_device	*spi = host->spi;
 	int			status, i;
 	struct scratch		*scratch = host->data;
+	u32			pattern;
 
 	if (host->mmc->use_spi_crc)
 		scratch->crc_val = cpu_to_be16(
@@ -636,8 +640,27 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
 	 * doesn't necessarily tell whether the write operation succeeded;
 	 * it just says if the transmission was ok and whether *earlier*
 	 * writes succeeded; see the standard.
+	 *
+	 * In practice, there are (even modern SDHC-)cards which are late
+	 * in sending the response, and miss the time frame by a few bits,
+	 * so we have to cope with this situation and check the response
+	 * bit-by-bit. Arggh!!!
 	 */
-	switch (SPI_MMC_RESPONSE_CODE(scratch->status[0])) {
+	pattern  = scratch->status[0] << 24;
+	pattern |= scratch->status[1] << 16;
+	pattern |= scratch->status[2] << 8;
+	pattern |= scratch->status[3];
+
+	/* First 3 bit of pattern are undefined */
+	pattern |= 0xE0000000;
+
+	/* left-adjust to leading 0 bit */
+	while (pattern & 0x80000000)
+		pattern <<= 1;
+	/* right-adjust for pattern matching. Code is in bit 4..0 now. */
+	pattern >>= 27;
+
+	switch (pattern) {
 	case SPI_RESPONSE_ACCEPTED:
 		status = 0;
 		break;
@@ -668,8 +691,9 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
 	/* Return when not busy.  If we didn't collect that status yet,
 	 * we'll need some more I/O.
 	 */
-	for (i = 1; i < sizeof(scratch->status); i++) {
-		if (scratch->status[i] != 0)
+	for (i = 4; i < sizeof(scratch->status); i++) {
+		/* card is non-busy if the most recent bit is 1 */
+		if (scratch->status[i] & 0x01)
 			return 0;
 	}
 	return mmc_spi_wait_unbusy(host, timeout);
@@ -1204,10 +1228,12 @@ static int mmc_spi_probe(struct spi_device *spi)
 
 	/* MMC and SD specs only seem to care that sampling is on the
 	 * rising edge ... meaning SPI modes 0 or 3.  So either SPI mode
-	 * should be legit.  We'll use mode 0 since it seems to be a
-	 * bit less troublesome on some hardware ... unclear why.
+	 * should be legit.  We'll use mode 0 since the steady state is 0,
+	 * which is appropriate for hotplugging, unless the platform data
+	 * specify mode 3 (if hardware is not compatible to mode 0).
 	 */
-	spi->mode = SPI_MODE_0;
+	if (spi->mode != SPI_MODE_3)
+		spi->mode = SPI_MODE_0;
 	spi->bits_per_word = 8;
 
 	status = spi_setup(spi);