Re: [PATCH 1/4] spi: lantiq: Synchronize interrupt handlers and transfers

[Dilip Kota]

On 4/28/2020 7:30 PM, Hauke Mehrtens wrote:
> On 4/28/20 1:10 PM, Daniel Schwierzeck wrote:
> > Am 24.04.20 um 12:42 schrieb Dilip Kota:
...
> Hi,
>
> The Interrupt controller found on Danube till xrx300 which is probably
> from Infineon like this SPI controller IP acknowledges the interrupts
> also inside this SPI controller IP automatically, this has to be done
> manually on the xrx500 and probably also LGM as they use a different
> interrupt controller. I prepared patches for this internally 2.5 years
> ago but did not send them upstream because of internal processes.
>
> I would suggest to only do this ack on the newer platforms starting with
> the xrx500 and not on the older.
>
> On SMP systems a lock is needed in lantiq_ssc_xmit_interrupt() to
> protect against an other thread reading from the RX buffer or writing to
> the TX buffer in parallel.
>
> @Dilip. Did you try the patches I send you one months ago on the LGM?
All the cases you mentioned are taken care in the patch, could you 
please have a look once.

And the patch you shared internally, has done below change. By referring 
it i have updated the offsets, mentioning offsets are wrong. But actual 
case is vrx200 are having different offsets and xrx500, latest chipsets 
are having different offsets. I think this could be the reason for SPI 
transfer timeouts when you run test on vrx200 with my patches.

-#define LTQ_SPI_IRNICR		0xf8
-#define LTQ_SPI_IRNCR		0xfc
+#define LTQ_SPI_IRNCR		0xf8
+#define LTQ_SPI_IRNICR		0xfc

These offsets need to be defined in SoC data structure as they are 
different across the chipsets(which i have done in initial phase of the 
patch which i submitted for internal review. I hope you had got a chance 
to review it).

Regards,
Dilip