Hi, Due the DMA api changes, please ignore this patch.
thanks Huang Shijie > [1] Background : > The GPMI does ECC read page operation with a DMA chain consist of three > DMA > Command Structures. The middle one of the chain is used to enable the BCH, > and read out the NAND page. > > The WAIT4END(wait for command end) is a comunication signal between > the GPMI and MXS-DMA. > > [2] The current DMA code sets the WAIT4END bit at the last one, such as: > > +-----+ +-----+ +-----+ > | cmd | ------------> | cmd | ------------------> | cmd | > +-----+ +-----+ +-----+ > ^ > | > | > set WAIT4END here > > This chain works fine in the mx23/mx28. > > [3] But in the new GPMI version (used in MX50/MX60), the WAIT4END bit should > be set not only at the last DMA Command Structure, > but also at the middle one, such as: > > +-----+ +-----+ +-----+ > | cmd | ------------> | cmd | ------------------> | cmd | > +-----+ +-----+ +-----+ > ^ ^ > | | > | | > set WAIT4END here too set WAIT4END here > > If we do not set WAIT4END, the BCH maybe stalls in "ECC reading page" > state. > In the next ECC write page operation, a DMA-timeout occurs. > This has been catched in the MX6Q board. > > [4] In order to fix the bug, rewrite the last parameter of > mxs_dma_prep_slave_sg(), > and use the dma_ctrl_flags: > --------------------------------------------------------- > DMA_PREP_INTERRUPT : append a new DMA Command Structrue. > DMA_CTRL_ACK : set the WAIT4END bit for this DMA Command > Structure. > --------------------------------------------------------- > > [5] changes to the relative drivers: > <1> For mxs-mmc driver, just use the new flags, do not change any logic. > <2> For gpmi-nand driver, add new field `gpmi_version` to distinguish > different gpmi versions, and use the new flags. > > Signed-off-by: Huang Shijie <[email protected]> > --- > drivers/dma/mxs-dma.c | 32 > ++++++++++++++++++++++++++++---- > drivers/mmc/host/mxs-mmc.c | 10 +++++----- > drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 28 ++++++++++++++++++++++------ > drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 4 ++++ > drivers/mtd/nand/gpmi-nand/gpmi-regs.h | 2 ++ > 5 files changed, 61 insertions(+), 15 deletions(-) > > diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c > index c80fbed..7d7498b 100644 > --- a/drivers/dma/mxs-dma.c > +++ b/drivers/dma/mxs-dma.c > @@ -349,10 +349,32 @@ static void mxs_dma_free_chan_resources(struct dma_chan > *chan) > clk_disable_unprepare(mxs_dma->clk); > } > > +/* > + * How to use the flags for ->device_prep_slave_sg() : > + * [1] If there is only one DMA command in the DMA chain, the code should > be: > + * ...... > + * ->device_prep_slave_sg(DMA_CTRL_ACK); > + * ...... > + * [2] If there are two DMA commands in the DMA chain, the code should be > + * ...... > + * ->device_prep_slave_sg(0); > + * ...... > + * ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > + * ...... > + * [3] If there are more than two DMA commands in the DMA chain, the code > + * should be: > + * ...... > + * ->device_prep_slave_sg(0); // > First > + * ...... > + * ->device_prep_slave_sg(DMA_PREP_INTERRUPT [| DMA_CTRL_ACK]); > + * ...... > + * ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); // > Last > + * ...... > + */ > static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg( > struct dma_chan *chan, struct scatterlist *sgl, > unsigned int sg_len, enum dma_transfer_direction direction, > - unsigned long append) > + unsigned long flags) > { > struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); > struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; > @@ -360,6 +382,7 @@ static struct dma_async_tx_descriptor > *mxs_dma_prep_slave_sg( > struct scatterlist *sg; > int i, j; > u32 *pio; > + bool append = flags & DMA_PREP_INTERRUPT; > int idx = append ? mxs_chan->desc_count : 0; > > if (mxs_chan->status == DMA_IN_PROGRESS && !append) > @@ -386,7 +409,6 @@ static struct dma_async_tx_descriptor > *mxs_dma_prep_slave_sg( > ccw->bits |= CCW_CHAIN; > ccw->bits &= ~CCW_IRQ; > ccw->bits &= ~CCW_DEC_SEM; > - ccw->bits &= ~CCW_WAIT4END; > } else { > idx = 0; > } > @@ -401,7 +423,8 @@ static struct dma_async_tx_descriptor > *mxs_dma_prep_slave_sg( > ccw->bits = 0; > ccw->bits |= CCW_IRQ; > ccw->bits |= CCW_DEC_SEM; > - ccw->bits |= CCW_WAIT4END; > + if (flags & DMA_CTRL_ACK) > + ccw->bits |= CCW_WAIT4END; > ccw->bits |= CCW_HALT_ON_TERM; > ccw->bits |= CCW_TERM_FLUSH; > ccw->bits |= BF_CCW(sg_len, PIO_NUM); > @@ -432,7 +455,8 @@ static struct dma_async_tx_descriptor > *mxs_dma_prep_slave_sg( > ccw->bits &= ~CCW_CHAIN; > ccw->bits |= CCW_IRQ; > ccw->bits |= CCW_DEC_SEM; > - ccw->bits |= CCW_WAIT4END; > + if (flags & DMA_CTRL_ACK) > + ccw->bits |= CCW_WAIT4END; > } > } > } > diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c > index 1e18970..120669b 100644 > --- a/drivers/mmc/host/mxs-mmc.c > +++ b/drivers/mmc/host/mxs-mmc.c > @@ -305,7 +305,7 @@ static irqreturn_t mxs_mmc_irq_handler(int irq, void > *dev_id) > } > > static struct dma_async_tx_descriptor *mxs_mmc_prep_dma( > - struct mxs_mmc_host *host, unsigned int append) > + struct mxs_mmc_host *host, unsigned long flags) > { > struct dma_async_tx_descriptor *desc; > struct mmc_data *data = host->data; > @@ -325,7 +325,7 @@ static struct dma_async_tx_descriptor *mxs_mmc_prep_dma( > } > > desc = host->dmach->device->device_prep_slave_sg(host->dmach, > - sgl, sg_len, host->slave_dirn, append); > + sgl, sg_len, host->slave_dirn, flags); > if (desc) { > desc->callback = mxs_mmc_dma_irq_callback; > desc->callback_param = host; > @@ -358,7 +358,7 @@ static void mxs_mmc_bc(struct mxs_mmc_host *host) > host->ssp_pio_words[2] = cmd1; > host->dma_dir = DMA_NONE; > host->slave_dirn = DMA_TRANS_NONE; > - desc = mxs_mmc_prep_dma(host, 0); > + desc = mxs_mmc_prep_dma(host, DMA_CTRL_ACK); > if (!desc) > goto out; > > @@ -398,7 +398,7 @@ static void mxs_mmc_ac(struct mxs_mmc_host *host) > host->ssp_pio_words[2] = cmd1; > host->dma_dir = DMA_NONE; > host->slave_dirn = DMA_TRANS_NONE; > - desc = mxs_mmc_prep_dma(host, 0); > + desc = mxs_mmc_prep_dma(host, DMA_CTRL_ACK); > if (!desc) > goto out; > > @@ -526,7 +526,7 @@ static void mxs_mmc_adtc(struct mxs_mmc_host *host) > host->data = data; > host->dma_dir = dma_data_dir; > host->slave_dirn = slave_dirn; > - desc = mxs_mmc_prep_dma(host, 1); > + desc = mxs_mmc_prep_dma(host, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > if (!desc) > goto out; > > diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c > b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c > index 7f68042..2029995 100644 > --- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c > +++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c > @@ -133,6 +133,9 @@ int gpmi_init(struct gpmi_nand_data *this) > if (ret) > goto err_out; > > + /* Read out the GPMI version */ > + this->gpmi_version = readl(r->gpmi_regs + HW_GPMI_VERSION); > + > /* Choose NAND mode. */ > writel(BM_GPMI_CTRL1_GPMI_MODE, r->gpmi_regs + HW_GPMI_CTRL1_CLR); > > @@ -839,7 +842,9 @@ int gpmi_send_command(struct gpmi_nand_data *this) > sg_init_one(sgl, this->cmd_buffer, this->command_length); > dma_map_sg(this->dev, sgl, 1, DMA_TO_DEVICE); > desc = channel->device->device_prep_slave_sg(channel, > - sgl, 1, DMA_MEM_TO_DEV, 1); > + sgl, 1, DMA_MEM_TO_DEV, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > + > if (!desc) { > pr_err("step 2 error\n"); > return -1; > @@ -881,7 +886,8 @@ int gpmi_send_data(struct gpmi_nand_data *this) > /* [2] send DMA request */ > prepare_data_dma(this, DMA_TO_DEVICE); > desc = channel->device->device_prep_slave_sg(channel, &this->data_sgl, > - 1, DMA_MEM_TO_DEV, 1); > + 1, DMA_MEM_TO_DEV, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > if (!desc) { > pr_err("step 2 error\n"); > return -1; > @@ -917,7 +923,8 @@ int gpmi_read_data(struct gpmi_nand_data *this) > /* [2] : send DMA request */ > prepare_data_dma(this, DMA_FROM_DEVICE); > desc = channel->device->device_prep_slave_sg(channel, &this->data_sgl, > - 1, DMA_DEV_TO_MEM, 1); > + 1, DMA_DEV_TO_MEM, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > if (!desc) { > pr_err("step 2 error\n"); > return -1; > @@ -964,7 +971,8 @@ int gpmi_send_page(struct gpmi_nand_data *this, > > desc = channel->device->device_prep_slave_sg(channel, > (struct scatterlist *)pio, > - ARRAY_SIZE(pio), DMA_TRANS_NONE, 0); > + ARRAY_SIZE(pio), DMA_TRANS_NONE, > + DMA_CTRL_ACK); > if (!desc) { > pr_err("step 2 error\n"); > return -1; > @@ -984,6 +992,7 @@ int gpmi_read_page(struct gpmi_nand_data *this, > struct dma_async_tx_descriptor *desc; > struct dma_chan *channel = get_dma_chan(this); > int chip = this->current_chip; > + unsigned long flags; > u32 pio[6]; > > /* [1] Wait for the chip to report ready. */ > @@ -1026,9 +1035,14 @@ int gpmi_read_page(struct gpmi_nand_data *this, > pio[3] = geo->page_size; > pio[4] = payload; > pio[5] = auxiliary; > + > + /* Check GPMI's version, set DMA_CTRL_ACK if needed. */ > + flags = DMA_PREP_INTERRUPT; > + if (this->gpmi_version == GPMI_VERSION_0501) > + flags |= DMA_CTRL_ACK; > desc = channel->device->device_prep_slave_sg(channel, > (struct scatterlist *)pio, > - ARRAY_SIZE(pio), DMA_TRANS_NONE, 1); > + ARRAY_SIZE(pio), DMA_TRANS_NONE, flags); > if (!desc) { > pr_err("step 2 error\n"); > return -1; > @@ -1045,9 +1059,11 @@ int gpmi_read_page(struct gpmi_nand_data *this, > | BF_GPMI_CTRL0_ADDRESS(address) > | BF_GPMI_CTRL0_XFER_COUNT(geo->page_size); > pio[1] = 0; > + pio[2] = 0; > desc = channel->device->device_prep_slave_sg(channel, > (struct scatterlist *)pio, 2, > - DMA_TRANS_NONE, 1); > + DMA_TRANS_NONE, > + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); > if (!desc) { > pr_err("step 3 error\n"); > return -1; > diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h > b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h > index 1c7fdbb..5c277e3 100644 > --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h > +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h > @@ -132,6 +132,10 @@ struct gpmi_nand_data { > /* Flash Hardware */ > struct nand_timing timing; > > + /* GPMI hardware version */ > +#define GPMI_VERSION_0501 (0x05010000) > + u32 gpmi_version; > + > /* BCH */ > struct bch_geometry bch_geometry; > struct completion bch_done; > diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-regs.h > b/drivers/mtd/nand/gpmi-nand/gpmi-regs.h > index 8343124..f005b24 100644 > --- a/drivers/mtd/nand/gpmi-nand/gpmi-regs.h > +++ b/drivers/mtd/nand/gpmi-nand/gpmi-regs.h > @@ -169,4 +169,6 @@ > #define HW_GPMI_DEBUG 0x000000c0 > #define MX23_BP_GPMI_DEBUG_READY0 28 > #define MX23_BM_GPMI_DEBUG_READY0 (1 << MX23_BP_GPMI_DEBUG_READY0) > + > +#define HW_GPMI_VERSION 0x000000d0 > #endif -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
