Hello, Erik!
You wrote to "Roman Mashak" <mrv@xxxxxxxxxxxxx> on Tue, 13 Feb 2007 13:13:33
+0100:
[skip]
??>> ...)' call. By the time of this call 'tx_buf' has been properly
??>> initialised and contains addresses of 4 TX descriptors. As I
??>> understand 'tx_bufs_dma' holds the physical address of DMA memory,
??>> while 'tx_bufs' - kernel virtual address. What I can't figure out is
??>> the point of this calculations: tp->tx_bufs_dma + (tp->tx_buf[i] -
??>> tp->tx_bufs) Why can't we simply have 'tp->tx_bufs_dma + (i * 4)' ?
EM> Probably because you can't assume that the buffer addresses are 4 bytes
EM> apart.
Why not? Every TX descriptor is of 32 bits length.
---
Best regards, Roman Mashak
--
To unsubscribe from this list: send an email with
"unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx
Please read the FAQ at http://kernelnewbies.org/FAQ
