Arindam, Capability to send CMD23 automatically is something specific to your controller. CMD23 (SET_BLOCK_COUNT) is a new command added in SD3.0 spec and mandatory for SDR104 mode. Why are you not adding this command in core/block layer before sending multi byte read command to host controller driver? Regards, Subhash > -----Original Message----- > From: linux-mmc-owner@xxxxxxxxxxxxxxx [mailto:linux-mmc- > owner@xxxxxxxxxxxxxxx] On Behalf Of Arindam Nath > Sent: Friday, March 04, 2011 5:03 PM > To: cjb@xxxxxxxxxx > Cc: zhangfei.gao@xxxxxxxxx; prakity@xxxxxxxxxxx; > subhashj@xxxxxxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; henry.su@xxxxxxx; > aaron.lu@xxxxxxx; anath.amd@xxxxxxxxx; Arindam Nath > Subject: [PATCH v2 01/12] mmc: sdhci: add support for auto CMD23 > > Host Controller v3.00 and later support Auto CMD23 in the Transfer > Mode register. Since Auto CMD23 can be used with or without DMA, > and if used with DMA, it should _only_ be ADMA, we check against > SDHCI_USE_SDMA not being set. This flag is reset when SDHCI_USE_ADMA > is set. > > A new definition for SDHCI_ARGUMENT2 register has been added in v3.00 > spec, which is the same as SDHCI_DMA_ADDRESS. We program the block > count for CMD23 in SDHCI_ARGUMENT2, so we don't need CMD12 to stop > multiple block transfers. But during error recovery procedure, we will > need to send Abort command, so we use a variable saved_abort_cmd to > save the stop command to be used later. > > Two bits are added to SCR register as per the Physical Layer Spec > v3.01, > which specify whether the card supports CMD20 and/or CMD23. We use this > as one of the conditions to decide whether to enable Auto CMD23 or not. > > Signed-off-by: Arindam Nath <arindam.nath@xxxxxxx> > --- > drivers/mmc/core/sd.c | 6 ++++ > drivers/mmc/host/sdhci.c | 69 > +++++++++++++++++++++++++++++++++++++++++--- > drivers/mmc/host/sdhci.h | 2 + > include/linux/mmc/card.h | 4 ++ > include/linux/mmc/sd.h | 2 +- > include/linux/mmc/sdhci.h | 2 + > 6 files changed, 79 insertions(+), 6 deletions(-) > > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c > index d18c32b..b3f8a3c 100644 > --- a/drivers/mmc/core/sd.c > +++ b/drivers/mmc/core/sd.c > @@ -188,6 +188,12 @@ static int mmc_decode_scr(struct mmc_card *card) > > scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4); > scr->bus_widths = UNSTUFF_BITS(resp, 48, 4); > + if (scr->sda_vsn == SCR_SPEC_VER_2) { > + /* Check if Physical Layer Spec v3.0 is supported*/ > + scr->sda_spec3 = UNSTUFF_BITS(resp, 47, 1); > + if (scr->sda_spec3) > + scr->cmd_support = UNSTUFF_BITS(resp, 32, 2); > + } > > if (UNSTUFF_BITS(resp, 55, 1)) > card->erased_byte = 0xFF; > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index 9e15f41..8914a25 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -25,6 +25,7 @@ > > #include <linux/mmc/mmc.h> > #include <linux/mmc/host.h> > +#include <linux/mmc/card.h> > > #include "sdhci.h" > > @@ -812,6 +813,30 @@ static void sdhci_prepare_data(struct sdhci_host > *host, struct mmc_data *data) > sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT); > } > > +/* > + * Does the Host Controller support Auto CMD23? > + * > + * There are four preconditions for Auto CMD23 to be supported: > + * 1. Host Controller v3.00 or later > + * 2. Card supports CMD23 > + * 3. If DMA is used, it should be ADMA > + * 4. Only when CMD18 or CMD25 is issued > + */ > +static int sdhci_host_auto_cmd23_supported(struct sdhci_host *host, > + struct mmc_request *mrq) > +{ > + struct mmc_card *card = host->mmc->card; > + > + if ((host->version >= SDHCI_SPEC_300) && > + card && (card->scr.cmd_support & SD_SCR_CMD23_SUPPORT) && > + !(host->flags & SDHCI_USE_SDMA) && > + ((mrq->cmd->opcode == MMC_READ_MULTIPLE_BLOCK) || > + (mrq->cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK))) > + return 1; > + > + return 0; > +} > + > static void sdhci_set_transfer_mode(struct sdhci_host *host, > struct mmc_data *data) > { > @@ -825,10 +850,21 @@ static void sdhci_set_transfer_mode(struct > sdhci_host *host, > mode = SDHCI_TRNS_BLK_CNT_EN; > if (data->blocks > 1) { > if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12) > - mode |= SDHCI_TRNS_MULTI | SDHCI_TRNS_ACMD12; > - else > - mode |= SDHCI_TRNS_MULTI; > + mode |= SDHCI_TRNS_ACMD12; > + else if (sdhci_host_auto_cmd23_supported(host, host->mrq)) > { > + /* > + * Host Controller v3.00 can automatically send CMD23 > + * before CMD18 or CMD25. For that, we need to enable > + * Auto CMD23 in the Transfer Mode register and > + * program the block count in Argument 2 register. > + */ > + mode |= SDHCI_TRNS_AUTO_CMD23; > + sdhci_writel(host, data->blocks, SDHCI_ARGUMENT2); > + } > + > + mode |= SDHCI_TRNS_MULTI; > } > + > if (data->flags & MMC_DATA_READ) > mode |= SDHCI_TRNS_READ; > if (host->flags & SDHCI_REQ_USE_DMA) > @@ -1131,6 +1167,23 @@ static void sdhci_request(struct mmc_host *mmc, > struct mmc_request *mrq) > #ifndef SDHCI_USE_LEDS_CLASS > sdhci_activate_led(host); > #endif > + /* > + * Since the block count for CMD23 has already been specified in > the > + * Argument 2 register, we don't need CMD12 to stop multiple > block > + * transfers. > + */ > + if (sdhci_host_auto_cmd23_supported(host, mrq)) { > + if (mrq->stop) { > + /* > + * Save the stop command here to be used during > + * error recovery > + */ > + host->saved_abort_cmd = mrq->data->stop; > + mrq->data->stop = NULL; > + mrq->stop = NULL; > + } > + } > + > if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12) { > if (mrq->stop) { > mrq->data->stop = NULL; > @@ -1396,6 +1449,7 @@ static void sdhci_timeout_timer(unsigned long > data) > > if (host->data) { > host->data->error = -ETIMEDOUT; > + host->data->stop = host->saved_abort_cmd; > sdhci_finish_data(host); > } else { > if (host->cmd) > @@ -1534,9 +1588,10 @@ static void sdhci_data_irq(struct sdhci_host > *host, u32 intmask) > host->data->error = -EIO; > } > > - if (host->data->error) > + if (host->data->error) { > + host->data->stop = host->saved_abort_cmd; > sdhci_finish_data(host); > - else { > + } else { > if (intmask & (SDHCI_INT_DATA_AVAIL | > SDHCI_INT_SPACE_AVAIL)) > sdhci_transfer_pio(host); > > @@ -1792,6 +1847,10 @@ int sdhci_add_host(struct sdhci_host *host) > host->flags &= ~SDHCI_USE_ADMA; > } > > + /* If the host can perform ADMA operation, we reset SDMA flag */ > + if (host->flags & SDHCI_USE_ADMA) > + host->flags &= ~SDHCI_USE_SDMA; > + > if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) { > if (host->ops->enable_dma) { > if (host->ops->enable_dma(host)) { > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h > index 6e0969e..223762c 100644 > --- a/drivers/mmc/host/sdhci.h > +++ b/drivers/mmc/host/sdhci.h > @@ -25,6 +25,7 @@ > */ > > #define SDHCI_DMA_ADDRESS 0x00 > +#define SDHCI_ARGUMENT2 SDHCI_DMA_ADDRESS > > #define SDHCI_BLOCK_SIZE 0x04 > #define SDHCI_MAKE_BLKSZ(dma, blksz) (((dma & 0x7) << 12) | (blksz & > 0xFFF)) > @@ -37,6 +38,7 @@ > #define SDHCI_TRNS_DMA 0x01 > #define SDHCI_TRNS_BLK_CNT_EN 0x02 > #define SDHCI_TRNS_ACMD12 0x04 > +#define SDHCI_TRNS_AUTO_CMD23 0x08 > #define SDHCI_TRNS_READ 0x10 > #define SDHCI_TRNS_MULTI 0x20 > > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 8ce0827..22b0335 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -58,9 +58,13 @@ struct mmc_ext_csd { > > struct sd_scr { > unsigned char sda_vsn; > + unsigned char sda_spec3; > unsigned char bus_widths; > #define SD_SCR_BUS_WIDTH_1 (1<<0) > #define SD_SCR_BUS_WIDTH_4 (1<<2) > + unsigned char cmd_support; > +#define SD_SCR_CMD20_SUPPORT (1<<0) > +#define SD_SCR_CMD23_SUPPORT (1<<1) > }; > > struct sd_ssr { > diff --git a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h > index 3fd85e0..178363b 100644 > --- a/include/linux/mmc/sd.h > +++ b/include/linux/mmc/sd.h > @@ -59,7 +59,7 @@ > > #define SCR_SPEC_VER_0 0 /* Implements system specification > 1.0 - 1.01 */ > #define SCR_SPEC_VER_1 1 /* Implements system specification > 1.10 */ > -#define SCR_SPEC_VER_2 2 /* Implements system specification > 2.00 */ > +#define SCR_SPEC_VER_2 2 /* Implements system specification > 2.00 - 3.0x */ > > /* > * SD bus widths > diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h > index 83bd9f7..282d158 100644 > --- a/include/linux/mmc/sdhci.h > +++ b/include/linux/mmc/sdhci.h > @@ -145,6 +145,8 @@ struct sdhci_host { > unsigned int ocr_avail_sd; > unsigned int ocr_avail_mmc; > > + struct mmc_command *saved_abort_cmd; /* Abort command saved > for data error recovery */ > + > unsigned long private[0] ____cacheline_aligned; > }; > #endif /* __SDHCI_H */ > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
