Dear Martyn, Manohar & all VME-users, I'm still struggling with my VME SBC & the VME-drivers... Please be so kind to have another look at the current situation: I got to the point that I had a board perfectly reading/writing data to another board, even with DMA calls to speed up things with a factor 8. Yesterday, we put the board in a production environment, and things have become quite complicated since then. (finally we get some sunshine in Belgium, but now clouds are covering my project...) Apparently, the existing VME-crate into which the new board was put, has a lot of VME bus errors in the existing traffic, as can be seen with a VME analyzer card. The existing legacy hardware/software cannot be modified however, so I'll have to live with this situation. These bus errors cause the TSI148 chipset to abort the read-calls, and generate an interrupt, which is caught by function 'tsi148_irqhandler()', and there some strange things happen... In the beginning of this function, the 'interrupt enable out' and 'interrupt status' registers are read out, as shown below: ... 260 /* Determine which interrupts are unmasked and set */ 261 enable = ioread32be(bridge->base + TSI148_LCSR_INTEO); 262 stat = ioread32be(bridge->base + TSI148_LCSR_INTS); ... The first time an interrupt occurs, both 'enable' and 'stat' are 0, which is not ok, since the 'enable' register is definitely set to a proper value when the 'vme_tsi1148' module is loaded/probed. A consecutive interrupt leads to value -1 (0xFFFFFFFF) for both 'enable' and 'stat', and then a kernel crash is not far way... In this case, all handlers (DMA, LM, MB, PERR, VERR, ...) are called, and inside these handlers, NULL pointers are dereferenced, leading to a crash. What could possibly be corrupting the TSI148_LCSR_INTEO and TSI148_LCSR_INTS registers ? Could it be the driver, or can it be the TSI148 chipset itself ? (e.g. can it be that the interrupt is raised before the registers are filled in correctly ?) Also, I can't find any good documentation on the difference between the 'interrupt enable out' and 'interrupt enable' registers. Do you have a clue ? Kind regards, Steven De Roo _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
