> My debugging result shows the underrun goes away if I put 2 printf's in the > harddisk ISR. The printf is at milli-seconds whereas the duration of the > original ISR is at lower magnitude. In addition, I find a SATA-PCI harddisk > does not have the underrun problem. IDE-PCI device gets the trouble.
Is the SATA controller on the motherboard and the PATA one on the PCI bus ? > So, do you have any idea about where the root cause can be hiding? Or what > do you think of adding printf's in ISR? (performance? incurring other > problems by disabling interrupt too long? On a standard PCI bus an IDE DMA disk can saturate the bus. That may be your underlying problem ? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
