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using PDC with SSC

Posted: Wed Feb 23, 2005 3:22 pm
by dapper
I've been trying to set up the PDC to write characters to one of the SSC ports. Everything appears to be set up correctly and I'm getting the interrupt when the PDC is done transmitting, but I never see anything on the transmit line of the SSC. If I write directly to the transmit buffer I see the characters at the output.
Is there something that needs to be initialized to transfer the characters between the PDC and SSC?

Posted: Wed Mar 02, 2005 1:35 pm
by Alexander Saers
Its because you are using virtual addresses that requires the mmu to resolve to the physical address.

Use the linux kernel function virt_to_bus to convert a virtual address to a physical. You must also use kmalloc with the __GFP_DMA flag to generate a physical continuous memory part