Message ID | 1346273254-24326-1-git-send-email-marex@denx.de |
---|---|
State | Rejected |
Headers | show |
> The final DMA descriptor doesn't properly write CTRL0 register > during the DMA transfer. Properly write CTRL0 to make sure the > transmission is complete. > > Signed-off-by: Marek Vasut <marex@denx.de> > Cc: Fabio Estevam <festevam@gmail.com> > Cc: Otavio Salvador <otavio@ossystems.com.br> > Cc: Stefano Babic <sbabic@denx.de> !! Please discard > --- > drivers/spi/mxs_spi.c | 20 +++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) > > diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c > index 168dbe4..5ee0ea1 100644 > --- a/drivers/spi/mxs_spi.c > +++ b/drivers/spi/mxs_spi.c > @@ -226,6 +226,7 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave > *slave, uint32_t cache_data_count; > int dmach; > int tl; > + int ret = 0; > > ALLOC_CACHE_ALIGN_BUFFER(struct mxs_dma_desc, desc, desc_count); > > @@ -302,12 +303,25 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave > *slave, MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM; > if (flags & SPI_XFER_END) { > ctrl0 &= ~SSP_CTRL0_LOCK_CS; > - dp->cmd.pio_words[0] = ctrl0 | SSP_CTRL0_IGNORE_CRC; > + ctrl0 |= SSP_CTRL0_IGNORE_CRC; > + dp->cmd.pio_words[0] = ctrl0; > } > mxs_dma_desc_append(dmach, dp); > > if (mxs_dma_go(dmach)) > - return -EINVAL; > + ret = -EINVAL; > + > + /* > + * The DMA contains further hidden gems, like the last transfer > + * not writing the CTRL0 PIO word properly. Write the PIO word > + * directly here for proper operation. This issue was detected > + * on S25FL064P chip by issuing: > + * > + * sf probe 2:0 ; sf read 0x42000000 0 0x800000 ; sf probe 2:0 > + * > + * This resulted in garbled subsequent probe. > + */ > + writel(ctrl0, &ssp_regs->hw_ssp_ctrl0_reg); > > /* The data arrived into DRAM, invalidate cache over them */ > if (!write) { > @@ -315,7 +329,7 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave > *slave, (uint32_t)(data + cache_data_count)); > } > > - return 0; > + return ret; > } > > int spi_xfer(struct spi_slave *slave, unsigned int bitlen, Best regards, Marek Vasut
On 01/09/2012 03:31, Marek Vasut wrote: >> The final DMA descriptor doesn't properly write CTRL0 register >> during the DMA transfer. Properly write CTRL0 to make sure the >> transmission is complete. >> >> Signed-off-by: Marek Vasut <marex@denx.de> >> Cc: Fabio Estevam <festevam@gmail.com> >> Cc: Otavio Salvador <otavio@ossystems.com.br> >> Cc: Stefano Babic <sbabic@denx.de> > > !! > > Please discard > Done ! Stefano
diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c index 168dbe4..5ee0ea1 100644 --- a/drivers/spi/mxs_spi.c +++ b/drivers/spi/mxs_spi.c @@ -226,6 +226,7 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave, uint32_t cache_data_count; int dmach; int tl; + int ret = 0; ALLOC_CACHE_ALIGN_BUFFER(struct mxs_dma_desc, desc, desc_count); @@ -302,12 +303,25 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave, MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM; if (flags & SPI_XFER_END) { ctrl0 &= ~SSP_CTRL0_LOCK_CS; - dp->cmd.pio_words[0] = ctrl0 | SSP_CTRL0_IGNORE_CRC; + ctrl0 |= SSP_CTRL0_IGNORE_CRC; + dp->cmd.pio_words[0] = ctrl0; } mxs_dma_desc_append(dmach, dp); if (mxs_dma_go(dmach)) - return -EINVAL; + ret = -EINVAL; + + /* + * The DMA contains further hidden gems, like the last transfer + * not writing the CTRL0 PIO word properly. Write the PIO word + * directly here for proper operation. This issue was detected + * on S25FL064P chip by issuing: + * + * sf probe 2:0 ; sf read 0x42000000 0 0x800000 ; sf probe 2:0 + * + * This resulted in garbled subsequent probe. + */ + writel(ctrl0, &ssp_regs->hw_ssp_ctrl0_reg); /* The data arrived into DRAM, invalidate cache over them */ if (!write) { @@ -315,7 +329,7 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave, (uint32_t)(data + cache_data_count)); } - return 0; + return ret; } int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
The final DMA descriptor doesn't properly write CTRL0 register during the DMA transfer. Properly write CTRL0 to make sure the transmission is complete. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Stefano Babic <sbabic@denx.de> --- drivers/spi/mxs_spi.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)