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Re: why should ISR arrange that the same interrupt would not recur until DSR completed?
- From: Stanislav Meduna <stano at meduna dot org>
- To: randyqiuxy <randyqiuxy at hotmail dot com>
- Cc: eCos Discussion <ecos-discuss at sourceware dot org>
- Date: Sun, 31 Mar 2013 14:05:48 +0200
- Subject: Re: why should ISR arrange that the same interrupt would not recur until DSR completed?
- References: <CA+QuBBfU01exmSPQQuXqhGOLASYa=4w32Gp=R0bR9DaUWvJJtA at mail dot gmail dot com>, <51546EFC dot 5050603 at dallaway dot org dot uk> <BLU0-SMTP3646F7EEA8206EF237E9FD3C3DD0 at phx dot gbl>
On 31.03.2013 10:10, Randy wrote:
> But why? If other interrupt could be enable when processing DSR, why
> is the same interrupt not allowed?
1) Other interrupt does not need to synchronize access to the hardware
and/or data structures shared between the ISR and corresponding DSR.
Remember, neither the ISR nor DSR can block. Disabling interrupts
outside of interrupt handlers is generally frowned upon.
2) The list of pending DSRs is now upper bounded. With the same
interrupt enabled it would become unbounded.
Regards
--
Stano
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