diff mbox series

[v2,06/15] spi: imx: fix ERR009165

Message ID 1556265512-9130-7-git-send-email-yibin.gong@nxp.com
State New, archived
Headers show
Series add ecspi ERR009165 for i.mx6/7 soc family | expand

Commit Message

Robin Gong April 26, 2019, 8:05 a.m. UTC
Change to XCH  mode even in dma mode, please refer to the below
errata:
https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
---
 drivers/spi/spi-imx.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

Comments

Lucas Stach April 26, 2019, 9:07 a.m. UTC | #1
Am Freitag, den 26.04.2019, 08:05 +0000 schrieb Robin Gong:
> Change to XCH  mode even in dma mode, please refer to the below
> errata:
> https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf
> 
> Signed-off-by: Robin Gong <yibin.gong@nxp.com>
> ---
>  drivers/spi/spi-imx.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
> index 09c9a1e..eb56eac 100644
> --- a/drivers/spi/spi-imx.c
> +++ b/drivers/spi/spi-imx.c
> @@ -585,8 +585,9 @@ static int mx51_ecspi_prepare_transfer(struct
> spi_imx_data *spi_imx,
>  	ctrl |= mx51_ecspi_clkdiv(spi_imx, t->speed_hz, &clk);
>  	spi_imx->spi_bus_clk = clk;
>  
> +	/* ERR009165: work in XHC mode as PIO */
>  	if (spi_imx->usedma)
> -		ctrl |= MX51_ECSPI_CTRL_SMC;
> +		ctrl &= ~MX51_ECSPI_CTRL_SMC;
>  
>  	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
>  
> @@ -612,12 +613,14 @@ static int mx51_ecspi_prepare_transfer(struct
> spi_imx_data *spi_imx,
>  
>  static void mx51_setup_wml(struct spi_imx_data *spi_imx)
>  {
> +	u32 tx_wml = 0;
> +

With a wml of 0 you might set the maxburst of the TX dma channel to
fifosize to minimize the performance impact of this workaround.

Regards,
Lucas

>  	/*
>  	 * Configure the DMA register: setup the watermark
>  	 * and enable DMA request.
>  	 */
>  	writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml - 1) |
> -		MX51_ECSPI_DMA_TX_WML(spi_imx->wml) |
> +		MX51_ECSPI_DMA_TX_WML(tx_wml) |
>  		MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |
>  		MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN |
>  		MX51_ECSPI_DMA_RXTDEN, spi_imx->base +
> MX51_ECSPI_DMA);
> @@ -1265,10 +1268,6 @@ static int spi_imx_sdma_init(struct device
> *dev, struct spi_imx_data *spi_imx,
>  {
>  	int ret;
>  
> -	/* use pio mode for i.mx6dl chip TKT238285 */
> -	if (of_machine_is_compatible("fsl,imx6dl"))
> -		return 0;
> -
>  	spi_imx->wml = spi_imx->devtype_data->fifo_size / 2;
>  
>  	/* Prepare for TX DMA: */
> -- 
> 2.7.4
>
Robin Gong April 26, 2019, 9:22 a.m. UTC | #2
On 2019-04-26 at 11:07 +0200, Lucas Stach wrote:
> 
> Am Freitag, den 26.04.2019, 08:05 +0000 schrieb Robin Gong:
> >  static void mx51_setup_wml(struct spi_imx_data *spi_imx)
> >  {
> > +     u32 tx_wml = 0;
> > +
> With a wml of 0 you might set the maxburst of the TX dma channel to
> fifosize to minimize the performance impact of this workaround.
> 
> Regards,
> Lucas
Unfortunately, this is a MUST part of errata which cause performance
drop.
Lucas Stach April 26, 2019, 9:37 a.m. UTC | #3
Am Freitag, den 26.04.2019, 09:22 +0000 schrieb Robin Gong:
> On 2019-04-26 at 11:07 +0200, Lucas Stach wrote:
> > 
> > Am Freitag, den 26.04.2019, 08:05 +0000 schrieb Robin Gong:
> > >  static void mx51_setup_wml(struct spi_imx_data *spi_imx)
> > >  {
> > > +     u32 tx_wml = 0;
> > > +
> > 
> > With a wml of 0 you might set the maxburst of the TX dma channel to
> > fifosize to minimize the performance impact of this workaround.
> > 
> > Regards,
> > Lucas
> 
> Unfortunately, this is a MUST part of errata which cause performance
> drop.

I'm not talking about changing the WML, but when the WML must be 0 you
can safely increase the DMA burst size without overflowing the FIFO,
which might recover some of of the performance loss.

Regards,
Lucas
Robin Gong April 26, 2019, 9:53 a.m. UTC | #4
On 2019-04-26 at 11:37 +0200, Lucas Stach wrote:
> Am Freitag, den 26.04.2019, 09:22 +0000 schrieb Robin Gong:
> > 
> > On 2019-04-26 at 11:07 +0200, Lucas Stach wrote:
> > > 
> > > 
> > > Am Freitag, den 26.04.2019, 08:05 +0000 schrieb Robin Gong:
> > > > 
> > > >  static void mx51_setup_wml(struct spi_imx_data *spi_imx)
> > > >  {
> > > > +     u32 tx_wml = 0;
> > > > +
> > > With a wml of 0 you might set the maxburst of the TX dma channel
> > > to
> > > fifosize to minimize the performance impact of this workaround.
> > > 
> > > Regards,
> > > Lucas
> > Unfortunately, this is a MUST part of errata which cause
> > performance
> > drop.
> I'm not talking about changing the WML, but when the WML must be 0
> you
> can safely increase the DMA burst size without overflowing the FIFO,
> which might recover some of of the performance loss.
> 
> Regards,
> Lucas
Good point, will add it in V3, thanks.
diff mbox series

Patch

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 09c9a1e..eb56eac 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -585,8 +585,9 @@  static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 	ctrl |= mx51_ecspi_clkdiv(spi_imx, t->speed_hz, &clk);
 	spi_imx->spi_bus_clk = clk;
 
+	/* ERR009165: work in XHC mode as PIO */
 	if (spi_imx->usedma)
-		ctrl |= MX51_ECSPI_CTRL_SMC;
+		ctrl &= ~MX51_ECSPI_CTRL_SMC;
 
 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
 
@@ -612,12 +613,14 @@  static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 
 static void mx51_setup_wml(struct spi_imx_data *spi_imx)
 {
+	u32 tx_wml = 0;
+
 	/*
 	 * Configure the DMA register: setup the watermark
 	 * and enable DMA request.
 	 */
 	writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml - 1) |
-		MX51_ECSPI_DMA_TX_WML(spi_imx->wml) |
+		MX51_ECSPI_DMA_TX_WML(tx_wml) |
 		MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |
 		MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN |
 		MX51_ECSPI_DMA_RXTDEN, spi_imx->base + MX51_ECSPI_DMA);
@@ -1265,10 +1268,6 @@  static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 {
 	int ret;
 
-	/* use pio mode for i.mx6dl chip TKT238285 */
-	if (of_machine_is_compatible("fsl,imx6dl"))
-		return 0;
-
 	spi_imx->wml = spi_imx->devtype_data->fifo_size / 2;
 
 	/* Prepare for TX DMA: */