From: ronald.wahl@raritan•com (Ronald Wahl)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] spi: atmel: fix corruption caused by too early transfer completion
Date: Thu, 07 Aug 2014 01:33:04 +0200 [thread overview]
Message-ID: <53E2BB30.1020009@raritan.com> (raw)
On 2014-08-06 13:00, Ronald Wahl wrote:
> The PDC (peripheral DMA controller) on AT91 supports two transfer
> counters and associated registers - one for current and one for the
> next transfer. If the current transfer is done the next transfer is
> moved into the current transfer. Now there are two interrupts: one is
> raised whenever a single transfer is done (ENDRX) and the other one is
> raised when the current and the next transfer has finished (RXBUFF).
> The issue is that the driver only enables the ENDRX interrupt which may
> lead to queuing a new request while there is still a transfer running.
> This can lead to overruns and/or corruption. By using the RXBUFF
> interrupt only we queue new requests only when the hardware queue is
> empty avoiding this problem.
Forgot to Cc: Nicolas Ferre ...
- ron
next reply other threads:[~2014-08-06 23:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-06 23:33 Ronald Wahl [this message]
-- strict thread matches above, loose matches on Subject: below --
2014-08-06 13:00 [PATCH] spi: atmel: fix corruption caused by too early transfer completion Ronald Wahl
2014-08-13 1:20 ` Yang, Wenyou
2014-08-13 6:16 ` Ludovic Desroches
2014-08-13 7:05 ` Yang, Wenyou
2014-08-13 8:13 ` Desroches, Ludovic
2014-08-13 8:26 ` Ronald Wahl
2014-08-13 9:16 ` Ludovic Desroches
2014-08-13 9:38 ` Ronald Wahl
2014-08-13 13:58 ` Ludovic Desroches
2014-08-13 8:20 ` Ronald Wahl
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