[PATCH v2] net: sh_eth: fix incorrect RX length error if R8A7740

[PATCH v2] net: sh_eth: fix incorrect RX length error if R8A7740

[Shimoda, Yoshihiro]

This patch fixes an issue that the driver increments the "RX length error"
on every buffer in sh_eth_rx() if the R8A7740.
This patch also adds a description about the Receive Frame Status bits.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 About v2:
  - This patch is based on the latest net.git.
  - Fix the description.

 drivers/net/ethernet/renesas/sh_eth.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index b4479b5..5e3982f 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1401,16 +1401,23 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status)
 		desc_status = edmac_to_cpu(mdp, rxdesc->status);
 		pkt_len = rxdesc->frame_length;

-#if defined(CONFIG_ARCH_R8A7740)
-		desc_status >>= 16;
-#endif
-
 		if (--boguscnt < 0)
 			break;

 		if (!(desc_status & RDFEND))
 			ndev->stats.rx_length_errors++;

+#if defined(CONFIG_ARCH_R8A7740)
+		/*
+		 * In case of almost all GETHER/ETHERs, the Receive Frame State
+		 * (RFS) bits in the Receive Descriptor 0 are from bit 9 to
+		 * bit 0. However, in case of the R8A7740's GETHER, the RFS
+		 * bits are from bit 25 to bit 16. So, the driver needs right
+		 * shifting by 16.
+		 */
+		desc_status >>= 16;
+#endif
+
 		if (desc_status & (RD_RFS1 | RD_RFS2 | RD_RFS3 | RD_RFS4 |
 				   RD_RFS5 | RD_RFS6 | RD_RFS10)) {
 			ndev->stats.rx_errors++;
-- 
1.7.1

Re: [PATCH v2] net: sh_eth: fix incorrect RX length error if R8A7740

[David Miller]

From: "Shimoda, Yoshihiro" <yoshihiro.shimoda.uh@renesas.com>
Date: Thu, 13 Jun 2013 10:15:45 +0900

> This patch fixes an issue that the driver increments the "RX length error"
> on every buffer in sh_eth_rx() if the R8A7740.
> This patch also adds a description about the Receive Frame Status bits.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Applied, thanks.

Re: [PATCH v2] net: sh_eth: fix incorrect RX length error if R8A7740

[Sergei Shtylyov]

Hello.

On 06/13/2013 02:02 PM, David Miller wrote:

>> This patch fixes an issue that the driver increments the "RX length error"
>> on every buffer in sh_eth_rx() if the R8A7740.
>> This patch also adds a description about the Receive Frame Status bits.

>> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

> Applied, thanks.

    I've already asked to do this but will you queue this for stable now?

WBR, Sergei

Re: [PATCH v2] net: sh_eth: fix incorrect RX length error if R8A7740

[David Miller]

From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Date: Thu, 13 Jun 2013 21:45:16 +0400

> Hello.
> 
> On 06/13/2013 02:02 PM, David Miller wrote:
> 
>>> This patch fixes an issue that the driver increments the "RX length
>>> error"
>>> on every buffer in sh_eth_rx() if the R8A7740.
>>> This patch also adds a description about the Receive Frame Status
>>> bits.
> 
>>> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> 
>> Applied, thanks.
> 
>    I've already asked to do this but will you queue this for stable now?

Done.