From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <43D41364.6000300@domain.hid> Date: Mon, 23 Jan 2006 00:21:08 +0100 From: Jan Kiszka MIME-Version: 1.0 References: In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig24A761DFEEA0BE6D63F7B769" Sender: jan.kiszka@domain.hid Subject: [Xenomai-core] Re: [PATCH] Shared irqs v.5 List-Id: "Xenomai life and development \(bug reports, patches, discussions\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Dmitry Adamushko Cc: xenomai@xenomai.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig24A761DFEEA0BE6D63F7B769 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Dmitry Adamushko wrote: > Hello Jan, >=20 > as I promised earlier today, here is the patch. I finally had a look at your patch (not yet a try), and it looks really nice and light-weight. Now I only have two topics on my wish list: o Handling of edge-triggered IRQs (ISA-cards...). As I tried to explain, in this case we have to run the IRQ handler list as long as the full list completed without any handler reporting XN_ISR_ENABLE back. Then and only then we are safe to not stall the IRQ line. See e.g. serial8250_interrupt() in linux/drivers/serial/8250.c for a per-driver solution and [1] for some discussion on sharing IRQs (be warned, it's from the evil side ;) ). On our systems we already have two of those use-cases: the xeno_16550A handling up to 4 devices on the same IRQ on an ISA card (I don't want to know what worst-case latency can be caused here...) and our SJA-1000 CAN driver for PC/104 ISA card with 2 controllers on the same interrupt line. So a common solution would reduce the code size and potential bug sources. o Store and display (/proc) the driver name(s) registered on an IRQ line somewhere (ipipe?). This is just a nice-to-have. I introduced the RTDM API with the required argument in place, would be great if we can use this some day. BTW, making the RTDM API shirq-aware should be as easy as adding some flags: one for sharing in general and maybe another one for marking edge-triggered IRQs. Jan PS: Still at home? How many degrees Centigrade? I guess our current -9=B0= C here in Hannover must appear ridiculous, almost subtropical warm to you. = ;) [1] http://www.microsoft.com/whdc/system/sysperf/apic.mspx --------------enig24A761DFEEA0BE6D63F7B769 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFD1BNkniDOoMHTA+kRAqEWAJ4kkRoQAkmBGDnEePYoICtWmoU6NgCfWXil oKS+K8bu0CeUOQxi1LNo1OM= =7nvx -----END PGP SIGNATURE----- --------------enig24A761DFEEA0BE6D63F7B769--