diff mbox

[v1,2/5] cadence_gem: Correct the multi-queue can rx logic

Message ID f65e921725d39ce81c2d0910d59897a020596c58.1491349058.git.alistair.francis@xilinx.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alistair Francis April 4, 2017, 11:40 p.m. UTC
Correct the buffer descriptor busy logic to work correctly when using
multiple queues.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
---

 hw/net/cadence_gem.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

Comments

Peter Maydell April 10, 2017, 12:37 p.m. UTC | #1
On 5 April 2017 at 00:40, Alistair Francis <alistair.francis@xilinx.com> wrote:
> Correct the buffer descriptor busy logic to work correctly when using
> multiple queues.
>
> Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
> ---
>
>  hw/net/cadence_gem.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
> index 17c229d..3e37665 100644
> --- a/hw/net/cadence_gem.c
> +++ b/hw/net/cadence_gem.c
> @@ -481,14 +481,18 @@ static int gem_can_receive(NetClientState *nc)
>      }
>
>      for (i = 0; i < s->num_priority_queues; i++) {
> -        if (rx_desc_get_ownership(s->rx_desc[i]) == 1) {
> -            if (s->can_rx_state != 2) {
> -                s->can_rx_state = 2;
> -                DB_PRINT("can't receive - busy buffer descriptor (q%d) 0x%x\n",
> -                         i, s->rx_desc_addr[i]);
> -             }
> -            return 0;
> +        if (rx_desc_get_ownership(s->rx_desc[i]) != 1) {
> +            break;
> +        }
> +    };
> +
> +    if (i == s->num_priority_queues) {
> +        if (s->can_rx_state != 2) {
> +            s->can_rx_state = 2;
> +            DB_PRINT("can't receive - busy buffer descriptor (q%d) 0x%x\n",
> +                     i, s->rx_desc_addr[i]);

This looks a little odd -- surely i isn't the right index to use
into rx_desc_addr[] any more now we're outside the loop and i
is always larger than the largest valid queue number? It looks
like the debug print should be rephrased somehow.

thanks
-- PMM
Alistair Francis April 10, 2017, 8:25 p.m. UTC | #2
On Mon, Apr 10, 2017 at 5:37 AM, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 5 April 2017 at 00:40, Alistair Francis <alistair.francis@xilinx.com> wrote:
>> Correct the buffer descriptor busy logic to work correctly when using
>> multiple queues.
>>
>> Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
>> ---
>>
>>  hw/net/cadence_gem.c | 18 +++++++++++-------
>>  1 file changed, 11 insertions(+), 7 deletions(-)
>>
>> diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
>> index 17c229d..3e37665 100644
>> --- a/hw/net/cadence_gem.c
>> +++ b/hw/net/cadence_gem.c
>> @@ -481,14 +481,18 @@ static int gem_can_receive(NetClientState *nc)
>>      }
>>
>>      for (i = 0; i < s->num_priority_queues; i++) {
>> -        if (rx_desc_get_ownership(s->rx_desc[i]) == 1) {
>> -            if (s->can_rx_state != 2) {
>> -                s->can_rx_state = 2;
>> -                DB_PRINT("can't receive - busy buffer descriptor (q%d) 0x%x\n",
>> -                         i, s->rx_desc_addr[i]);
>> -             }
>> -            return 0;
>> +        if (rx_desc_get_ownership(s->rx_desc[i]) != 1) {
>> +            break;
>> +        }
>> +    };
>> +
>> +    if (i == s->num_priority_queues) {
>> +        if (s->can_rx_state != 2) {
>> +            s->can_rx_state = 2;
>> +            DB_PRINT("can't receive - busy buffer descriptor (q%d) 0x%x\n",
>> +                     i, s->rx_desc_addr[i]);
>
> This looks a little odd -- surely i isn't the right index to use
> into rx_desc_addr[] any more now we're outside the loop and i
> is always larger than the largest valid queue number? It looks
> like the debug print should be rephrased somehow.

Yeah you are right. It means that they are all busy, we can either
iterate over all of them and print out this or just print one
statement saying that. Somehow I ended up half way between both.

I'll update it to just print that they are all busy. I don't see why
we need every address printed.

Thanks,

Alistair

>
> thanks
> -- PMM
diff mbox

Patch

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index 17c229d..3e37665 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -481,14 +481,18 @@  static int gem_can_receive(NetClientState *nc)
     }
 
     for (i = 0; i < s->num_priority_queues; i++) {
-        if (rx_desc_get_ownership(s->rx_desc[i]) == 1) {
-            if (s->can_rx_state != 2) {
-                s->can_rx_state = 2;
-                DB_PRINT("can't receive - busy buffer descriptor (q%d) 0x%x\n",
-                         i, s->rx_desc_addr[i]);
-             }
-            return 0;
+        if (rx_desc_get_ownership(s->rx_desc[i]) != 1) {
+            break;
+        }
+    };
+
+    if (i == s->num_priority_queues) {
+        if (s->can_rx_state != 2) {
+            s->can_rx_state = 2;
+            DB_PRINT("can't receive - busy buffer descriptor (q%d) 0x%x\n",
+                     i, s->rx_desc_addr[i]);
         }
+        return 0;
     }
 
     if (s->can_rx_state != 0) {