Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cwjcc!gatech!rutgers!mailrus!uwmcsd1!ig!agate!ucbvax!WEGENER.MIT.EDU!krowitz From: krowitz@WEGENER.MIT.EDU (David Krowitz) Newsgroups: comp.sys.apollo Subject: GPIO help Message-ID: <8809212330.AA16999@wegener.mit.edu> Date: 21 Sep 88 23:30:51 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 25 I'm trying to write a device driver for an AT bus card using a similar multibus card's driver as an example, and I don't quite understand the interrupt library for an AT device. With the multibus device, I just load up the command register of the device to initiate the DMA operation. With the AT device, it looks like I should be calling pbu_$dma_start to set up the CPU's DMA hardware. When I bind the interrupt library, the binder reports that all globals are resolved, yet when I try to aquire the device with /com/aqdev I get a message about the library containing unresolved globals. If I remove the call to pbu_$dma_start from the interrupt library and rebind it I can then aquire the device (but I can use it since there is no way to start the DMA). The call to pbu_$dma_start is the only GPIO call in the interrupt library. It it legal to make GPIO calls from the interrupt level? If not, how do I initiate the DMA transfer? -- David Krowitz krowitz@richter.mit.edu (18.83.0.109) krowitz%richter@eddie.mit.edu krowitz%richter@athena.mit.edu krowitz%richter.mit.edu@mitvma.bitnet (in order of decreasing preference)