From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MnEqE-0002J7-RT for qemu-devel@nongnu.org; Mon, 14 Sep 2009 12:55:50 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MnEqA-0002Fn-9R for qemu-devel@nongnu.org; Mon, 14 Sep 2009 12:55:50 -0400 Received: from [199.232.76.173] (port=42381 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MnEqA-0002Fe-1T for qemu-devel@nongnu.org; Mon, 14 Sep 2009 12:55:46 -0400 Received: from mail-ew0-f221.google.com ([209.85.219.221]:53087) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MnEq9-00032D-Df for qemu-devel@nongnu.org; Mon, 14 Sep 2009 12:55:45 -0400 Received: by ewy21 with SMTP id 21so2932905ewy.8 for ; Mon, 14 Sep 2009 09:55:43 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1252943364-32705-9-git-send-email-kraxel@redhat.com> References: <1252943364-32705-1-git-send-email-kraxel@redhat.com> <1252943364-32705-9-git-send-email-kraxel@redhat.com> From: Blue Swirl Date: Mon, 14 Sep 2009 19:55:23 +0300 Message-ID: Subject: Re: [Qemu-devel] [PATCH 8/9] isa: refine irq reservations Content-Type: multipart/mixed; boundary=001636c5b94a4fb95704738c8993 List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: qemu-devel@nongnu.org --001636c5b94a4fb95704738c8993 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Mon, Sep 14, 2009 at 6:49 PM, Gerd Hoffmann wrote: > There are a few cases where IRQ sharing on the ISA bus is used and > possible. =C2=A0In general only devices of the same kind can do that. > A few use cases: > > =C2=A0* serial lines 1+3 share irq 4 > =C2=A0* serial lines 2+4 share irq 3 > =C2=A0* parallel ports share irq 7 > =C2=A0* ppc/prep: ide ports share irq 13 There is another ppc/prep case where RTC and m48t59 share irq 8. The attached patch converts m48t59 to ISA and makes this more visible. Does sharing of IRQs really have to be fatal? Wasn't ISA bus edge triggered and so IRQ sharing was a bit unreliable (but not completely broken) also on real HW? --001636c5b94a4fb95704738c8993 Content-Type: application/mbox; name="0001-PPC-use-ISA-version-of-m48t59-for-PREP-machine.patch" Content-Disposition: attachment; filename="0001-PPC-use-ISA-version-of-m48t59-for-PREP-machine.patch" Content-Transfer-Encoding: base64 X-Attachment-Id: f_fzlgcqbj0 RnJvbSBlNTc1NTAyY2YyMGQ3MzU2MThhOTYzNDZlNmQ5ODU0ZWRhZjkyZmE4IE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBCbHVlIFN3aXJsIDxibGF1d2lyYmVsQGdtYWlsLmNvbT4KRGF0 ZTogTW9uLCAxNCBTZXAgMjAwOSAxNjo1MToxNyArMDAwMApTdWJqZWN0OiBbUEFUQ0hdIFBQQzog dXNlIElTQSB2ZXJzaW9uIG9mIG00OHQ1OSBmb3IgUFJFUCBtYWNoaW5lCgpTaWduZWQtb2ZmLWJ5 OiBCbHVlIFN3aXJsIDxibGF1d2lyYmVsQGdtYWlsLmNvbT4KLS0tCiBody9wcGNfcHJlcC5jIHwg ICAgMiArLQogMSBmaWxlcyBjaGFuZ2VkLCAxIGluc2VydGlvbnMoKyksIDEgZGVsZXRpb25zKC0p CgpkaWZmIC0tZ2l0IGEvaHcvcHBjX3ByZXAuYyBiL2h3L3BwY19wcmVwLmMKaW5kZXggNzQzZGFk Mi4uMGVkMDdjZSAxMDA2NDQKLS0tIGEvaHcvcHBjX3ByZXAuYworKysgYi9ody9wcGNfcHJlcC5j CkBAIC03NTEsNyArNzUxLDcgQEAgc3RhdGljIHZvaWQgcHBjX3ByZXBfaW5pdCAocmFtX2FkZHJf dCByYW1fc2l6ZSwKICAgICAgICAgdXNiX29oY2lfaW5pdF9wY2kocGNpX2J1cywgLTEpOwogICAg IH0KIAotICAgIG00OHQ1OSA9IG00OHQ1OV9pbml0KGk4MjU5WzhdLCAwLCAweDAwNzQsIE5WUkFN X1NJWkUsIDU5KTsKKyAgICBtNDh0NTkgPSBtNDh0NTlfaW5pdF9pc2EoMHgwMDc0LCBOVlJBTV9T SVpFLCA1OSk7CiAgICAgaWYgKG00OHQ1OSA9PSBOVUxMKQogICAgICAgICByZXR1cm47CiAgICAg c3lzY3RybC0+bnZyYW0gPSBtNDh0NTk7Ci0tIAoxLjUuNi41Cgo= --001636c5b94a4fb95704738c8993--