Re: [PATCH] cpsw: Fix interrupt storm among other things

From: Mugunthan V N
Date: Wed Jan 30 2013 - 14:28:26 EST


Hi Antoniou

On 1/30/2013 7:25 PM, Pantelis Antoniou wrote:
Hi Mugunthan,

On Jan 30, 2013, at 3:53 PM, Mugunthan V N wrote:

On 1/30/2013 7:21 PM, Pantelis Antoniou wrote:
Hi Vaibhav,

On Jan 30, 2013, at 3:47 PM, Bedia, Vaibhav wrote:

Hi Antoniou,

On Wed, Jan 30, 2013 at 19:07:19, Pantelis Antoniou wrote:
Hi Vaibhav,

On Jan 30, 2013, at 3:29 PM, Bedia, Vaibhav wrote:

On Wed, Jan 30, 2013 at 18:14:30, Pantelis Antoniou wrote:
Hi Vaibhav,

On Jan 30, 2013, at 2:38 PM, Bedia, Vaibhav wrote:

On Wed, Jan 30, 2013 at 16:38:50, Pantelis Antoniou wrote:
[...]
TBH I haven't found a simple way to print out the silicon revision number.
Anyone on the list know a quick and dirty method?

You can dump the DEVICE_ID register @ 0x44e10600.
Bits 31:28 should be 0 for PG1.0 and 1 for PG2.0.

Thanks this works perfectly:

original-bone:
root@beaglebone:~# devmem2 0x44e10600 w
Read at address 0x44E10600 (0xb6ff4600): 0x0B94402E

bone-black:
root@beaglebone:~# devmem2 0x44e10600 w
Read at address 0x44E10600 (0xb6fcc600): 0x1B94402E

I just re-read the mail-chain and I am confused here.
So the patch in question is meant for Bone-A4 which has
PG1.0?

It is a general bug fix. The problem was discovered only on
the bone black which has PG2.0 silicon. The driver has been
tested and it works on the original bone with PG1.0 as well.

But Mugunthan mentioned that he doesn't see this on an EVM
with PG2.0 silicon... is there any board dependency here?

I don't know, but I doubt it. How about we wait for Mugunthan to
send us what are the DEVICE_ID contents for his board.

Regards,
Vaibhav
Regards

-- Pantelis

This is the device ID which i have

[root@arago /]# devmem 0x44e10600
0x1B94402E

No clue what's the difference of the black with the EVM, and why this happens.
The fix is valid anyway.
I am able to see the issue in EVM also by comparing the number of rx interrupt received
from CPSW and no of packets actually received. But this can be resolved by acknowledging
the interrupt in cpdma driver.

Regards
Mugunthan V N
Regards
Mugunthan V N
Regards

-- Pantelis


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