[PATCH (net-next.git)] STMMAC: fix TX Normal descriptor

[PATCH (net-next.git)] STMMAC: fix TX Normal descriptor

[Giuseppe Cavallaro]

On top of the Oct_2015 driver version committed into net-next, this patch
fixes a problem for the HW where the normal descriptor are used at runtime
instead of the Enhanced/Alternate descriptors.
In the beginning, it was suggested to revert the patch:
  "stmmac: first frame prep at the end of xmit routine"
and it has been noticed that w/o it the normal TDES 0 and 1 were good filled.

Then has been proposed this new fix (w/o reverting the patch above).

Giuseppe Cavallaro (1):
  stmmac: fix TX normal DESC

 drivers/net/ethernet/stmicro/stmmac/norm_desc.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

-- 
1.7.4.4

[PATCH (net-next.git)] stmmac: fix TX normal DESC

[Giuseppe Cavallaro]

This patch fixs a regression raised when test on chips that use
the normal descriptor layout. In fact, no len bits were set for
the TDES1 and no OWN bit inside the TDES0.

Signed-off-by: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Cc: Fabrice Gasnier <fabrice.gasnier@st.com>
---
 drivers/net/ethernet/stmicro/stmmac/norm_desc.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
index e13228f..011386f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
@@ -199,11 +199,6 @@ static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
 {
 	unsigned int tdes1 = p->des1;
 
-	if (mode == STMMAC_CHAIN_MODE)
-		norm_set_tx_desc_len_on_chain(p, len);
-	else
-		norm_set_tx_desc_len_on_ring(p, len);
-
 	if (is_fs)
 		tdes1 |= TDES1_FIRST_SEGMENT;
 	else
@@ -217,10 +212,15 @@ static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
 	if (ls)
 		tdes1 |= TDES1_LAST_SEGMENT;
 
-	if (tx_own)
-		tdes1 |= TDES0_OWN;
-
 	p->des1 = tdes1;
+
+	if (mode == STMMAC_CHAIN_MODE)
+		norm_set_tx_desc_len_on_chain(p, len);
+	else
+		norm_set_tx_desc_len_on_ring(p, len);
+
+	if (tx_own)
+		p->des0 |= TDES0_OWN;
 }
 
 static void ndesc_set_tx_ic(struct dma_desc *p)
-- 
1.7.4.4

Re: [PATCH (net-next.git)] stmmac: fix TX normal DESC

[Tomeu Vizoso]

On 16 March 2016 at 11:21, Giuseppe Cavallaro <peppe.cavallaro@st.com> wrote:
> This patch fixs a regression raised when test on chips that use
> the normal descriptor layout. In fact, no len bits were set for
> the TDES1 and no OWN bit inside the TDES0.
>
> Signed-off-by: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
> Tested-by: Andreas Färber <afaerber@suse.de>
> Cc: Fabrice Gasnier <fabrice.gasnier@st.com>

Hi,

with this patch, I have eth working reliably on the Rock2 again.

Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

Thanks,

Tomeu

> ---
>  drivers/net/ethernet/stmicro/stmmac/norm_desc.c |   16 ++++++++--------
>  1 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
> index e13228f..011386f 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
> @@ -199,11 +199,6 @@ static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
>  {
>         unsigned int tdes1 = p->des1;
>
> -       if (mode == STMMAC_CHAIN_MODE)
> -               norm_set_tx_desc_len_on_chain(p, len);
> -       else
> -               norm_set_tx_desc_len_on_ring(p, len);
> -
>         if (is_fs)
>                 tdes1 |= TDES1_FIRST_SEGMENT;
>         else
> @@ -217,10 +212,15 @@ static void ndesc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
>         if (ls)
>                 tdes1 |= TDES1_LAST_SEGMENT;
>
> -       if (tx_own)
> -               tdes1 |= TDES0_OWN;
> -
>         p->des1 = tdes1;
> +
> +       if (mode == STMMAC_CHAIN_MODE)
> +               norm_set_tx_desc_len_on_chain(p, len);
> +       else
> +               norm_set_tx_desc_len_on_ring(p, len);
> +
> +       if (tx_own)
> +               p->des0 |= TDES0_OWN;
>  }
>
>  static void ndesc_set_tx_ic(struct dma_desc *p)
> --
> 1.7.4.4
>