From: Ernst Schwab <[email protected]> Added spi_register_lock_bus call to mmc_spi, removed code that counts the number of SPI devices.
Signed-off-by: Ernst Schwab <[email protected]> --- diff -upr a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c --- a/drivers/mmc/host/mmc_spi.c +++ b/drivers/mmc/host/mmc_spi.c @@ -1083,8 +1083,10 @@ static void mmc_spi_request(struct mmc_h } #endif - /* issue command; then optionally data and stop */ + /* request exclusive bus access */ spi_lock_bus(host->spi); + + /* issue command; then optionally data and stop */ status = mmc_spi_command_send(host, mrq, mrq->cmd, mrq->data != NULL); if (status == 0 && mrq->data) { mmc_spi_data_do(host, mrq->cmd, mrq->data, mrq->data->blksz); @@ -1093,7 +1095,10 @@ static void mmc_spi_request(struct mmc_h else mmc_cs_off(host); } + + /* release the bus */ spi_unlock_bus(host->spi); + mmc_request_done(host->mmc, mrq); } @@ -1290,23 +1295,6 @@ mmc_spi_detect_irq(int irq, void *mmc) return IRQ_HANDLED; } -struct count_children { - unsigned n; - struct bus_type *bus; -}; - -static int maybe_count_child(struct device *dev, void *c) -{ - struct count_children *ccp = c; - - if (dev->bus == ccp->bus) { - if (ccp->n) - return -EBUSY; - ccp->n++; - } - return 0; -} - static int mmc_spi_probe(struct spi_device *spi) { void *ones; @@ -1338,6 +1326,13 @@ static int mmc_spi_probe(struct spi_devi return status; } + /* Ensure that the driver can get exclusive access. */ + status = spi_register_lock_bus(spi); + if (status < 0) { + dev_err(&spi->dev, "can't share SPI bus\n"); + return -EBUSY; + } + /* We need a supply of ones to transmit. This is the only time * the CPU touches these, so cache coherency isn't a concern. * @@ -1471,6 +1466,7 @@ fail_nobuf1: nomem: kfree(ones); + spi_unregister_lock_bus(spi); return status; } @@ -1503,6 +1499,7 @@ static int __devexit mmc_spi_remove(stru mmc_free_host(mmc); mmc_spi_put_pdata(spi); dev_set_drvdata(&spi->dev, NULL); + spi_unregister_lock_bus(spi); } return 0; } ------------------------------------------------------------------------------ SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
