[PATCH] mmc: atmel-mci: not busy flag has also to be used for read operations
From: ludovic.desroches at atmel.com <hidden>
Date: 2012-07-24 09:42:04
Also in:
linux-mmc
Subsystem:
microchip mmc/sd/sdio mci driver, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Aubin Constans, Ulf Hansson, Linus Torvalds
From: Ludovic Desroches <redacted> Even if the datasheet says that the not busy flag has to be used only for write operations, it's false excepted for version lesser than v2xx. Not waiting the not busy flag for read operations can cause the controller to hang-up during the initialization of some SD cards. Signed-off-by: Ludovic Desroches <redacted> Cc: stable at vger.kernel.org Hello, This is a fix for 3.5 and later. Due to the big changes into atmel-mci driver to support all atmel mci versions, a bug was introduced. With some SD cards (mainly micro) when using DMA, the controller hangs-up after the first CMD6 command because the next command is sent too early. Regards Ludovic --- drivers/mmc/host/atmel-mci.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index f2c115e..b6abfa7 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c@@ -81,6 +81,7 @@ struct atmel_mci_caps { bool has_bad_data_ordering; bool need_reset_after_xfer; bool need_blksz_mul_4; + bool need_notbusy_for_read_ops; }; struct atmel_mci_dma {
@@ -1619,7 +1620,8 @@ static void atmci_tasklet_func(unsigned long priv) __func__); atmci_set_completed(host, EVENT_XFER_COMPLETE); - if (host->data->flags & MMC_DATA_WRITE) { + if (host->caps.need_notbusy_for_read_ops + || (host->data->flags & MMC_DATA_WRITE)) { atmci_writel(host, ATMCI_IER, ATMCI_NOTBUSY); state = STATE_WAITING_NOTBUSY; } else if (host->mrq->stop) {
@@ -2212,6 +2214,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) host->caps.has_bad_data_ordering = 1; host->caps.need_reset_after_xfer = 1; host->caps.need_blksz_mul_4 = 1; + host->caps.need_notbusy_for_read_ops = 0; /* keep only major version number */ switch (version & 0xf00) {
@@ -2232,6 +2235,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) case 0x200: host->caps.has_rwproof = 1; host->caps.need_blksz_mul_4 = 0; + host->caps.need_notbusy_for_read_ops = 1; case 0x100: host->caps.has_bad_data_ordering = 0; host->caps.need_reset_after_xfer = 0;
--
1.7.5.4