Please read more comment in the mxs-dma.h.
In the new GPMI version(0x05010000 used by MX6Q/MX50), we should
set the WAIT4END bit in the middle one of this chain,
which enables the BCH module and reads out the NAND page.
If we do not do this, a DMA timeout occurs. This bug has been
catched in the MX6Q board.
We have changed the DMA interface to fix the bug, now use the new
interface.
Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx>
---
drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 20 ++++++++++++++------
1 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
index 5b73ae5..84abd49 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
@@ -842,7 +842,7 @@ 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, MXS_DMA_F_LASTONE);
if (!desc) {
pr_err("step 2 error\n");
return -1;
@@ -884,7 +884,7 @@ 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, MXS_DMA_F_LASTONE);
if (!desc) {
pr_err("step 2 error\n");
return -1;
@@ -920,7 +920,7 @@ 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, MXS_DMA_F_LASTONE);
if (!desc) {
pr_err("step 2 error\n");
return -1;
@@ -967,7 +967,8 @@ 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,
+ MXS_DMA_F_WAIT4END);
if (!desc) {
pr_err("step 2 error\n");
return -1;
@@ -987,6 +988,7 @@ 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. */
@@ -1029,9 +1031,14 @@ int gpmi_read_page(struct gpmi_nand_data *this,
pio[3] = geo->page_size;
pio[4] = payload;
pio[5] = auxiliary;
+
+ /* If the GPMI is new version, set MXS_DMA_F_WAIT4END here. */
+ flags = MXS_DMA_F_APPEND;
+ if (this->gpmi_version == GPMI_VERSION_0501)
+ flags |= MXS_DMA_F_WAIT4END;
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;
@@ -1048,9 +1055,10 @@ 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, MXS_DMA_F_LASTONE);
if (!desc) {
pr_err("step 3 error\n");
return -1;
--
1.7.0.4
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