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Groups > linux.kernel > #1340593
| From | Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 0/4] serial: omap: robustify for high speed transfers |
| Date | 2016-02-23 13:50 +0100 |
| Message-ID | <r5kzD-5tk-5@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <qXUqB-3w4-1@gated-at.bofh.it> <r0Yeo-8w1-47@gated-at.bofh.it> <r16EW-5RN-5@gated-at.bofh.it> <r50KB-7Jl-1@gated-at.bofh.it> <r5i4P-3MQ-25@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 02/23/2016 10:59 AM, Sekhar Nori wrote: >> With the am335x (Beaglebone Black, eDMA engine) I see 1000 DMA >> interrupts and 1000 spurious UART interrupts. The spurious UART >> interrupts arrive 30-50us _before_ the DMA interrupts. Always. >> >> If I disable UART timeout interrupts (RDI), the same test generates no >> spurious UART interrupts. Only 1000 DMA interrupts. > > To be clear, these interrupts are not caught as spurious by the > interrupt controller (INTC). They are detected by INTC as UART > interrupts. Just that you don't expect a timeout interrupt to happen at > the time you see the interrupt, correct? From what I remember the INTC says it is UART, correct. But UART's status register says "no interrupt" (IIR has UART_IIR_NO_INT set). So the UART driver returns IRQ_NONE which counts as spurious. It is just that once you disable RDI there are no more interrupts coming during DMA transfer. > Thanks, > Sekhar > Sebastian
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Re: [PATCH 0/4] serial: omap: robustify for high speed transfers Sekhar Nori <nsekhar@ti.com> - 2016-02-23 11:10 +0100
Re: [PATCH 0/4] serial: omap: robustify for high speed transfers Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-02-23 13:50 +0100
Re: [PATCH 0/4] serial: omap: robustify for high speed transfers Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-02-23 18:00 +0100
Re: [PATCH 0/4] serial: omap: robustify for high speed transfers Peter Hurley <peter@hurleysoftware.com> - 2016-02-24 04:30 +0100
Re: [PATCH 0/4] serial: omap: robustify for high speed transfers Sekhar Nori <nsekhar@ti.com> - 2016-02-24 16:40 +0100
Re: [PATCH 0/4] serial: omap: robustify for high speed transfers Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-02-24 16:50 +0100
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