Re: [rt2x00-users] [PATCH 1/7] rt2x00: rt2x00dev: use rt2x00dev->tx->limit

[Gabor Juhos <juhosg@openwrt.org>]

Hi Kuba!

> On Wed,  1 May 2013 17:17:29 +0200, Gabor Juhos wrote:
>> The TX data queue is initialized already when
>> the rt2x00lib_probe_hw() function is called.
>>
>> Fetch the number of the queue entries from that
>> instead of using the entry_num field of the data
>> queue descriptor.
>>
>> The two values are the same, and the use of the
>> rt2x00dev->tx->limit value allows us to get rid
>> of a superfluous pointer dereference.
>>
>> Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
>> ---
>>  drivers/net/wireless/rt2x00/rt2x00dev.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
>> index 90dc143..b287467 100644
>> --- a/drivers/net/wireless/rt2x00/rt2x00dev.c
>> +++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
>> @@ -1077,7 +1077,7 @@ static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
>>   		 */
>>  		int kfifo_size =
>>  			roundup_pow_of_two(rt2x00dev->ops->tx_queues *
>> -					   rt2x00dev->ops->tx->entry_num *
>> +					   rt2x00dev->tx->limit *
>>  					   sizeof(u32));
>>  
>>  		status = kfifo_alloc(&rt2x00dev->txstatus_fifo, kfifo_size,
> 
> Unfortunately this does not work without your "get rid of
> static data queue descriptors" series as well.
> 
> queue->limit is set when rt2x00lib_start is called, not on
> probe. kfifo_alloc will fail with EINVAL here. 

You are right. I should have been more careful while I have tested this patch-set.

> As a result support for all rt2x00 devices is broken on wireless-testing.

Only rt2800 devices are affected. The offending code runs only if
REQUIRE_TXSTATUS_FIFO is set in rt2x00dev->cap_flags which is not set for older
chips.

> Maybe you can just post the mentioned series for inclusion?

I will post a fix for the actual problem first, and will rebase the series on
top of that.

> I have been running with it since you posted it as RFC and
> I did not notice any problems so far...

Great!

-Gabor