Thanks for the tip Sergei. The timeout in question lasts several seconds and is unrecoverable, finishing with a bus error. I could be looking at a hardware problem, but I have tried different drives, cables and I even see it on different units. And most of the times everything works fine. Regards, Alex On Sat, Sep 13, 2008 at 1:55 PM, Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx> wrote: > Hello. > > Alex Gonzalez wrote: >> >> I am seeing a problem with libata and the sata_sil driver. I was >> redirected here from the lkml so I hope it's the correct list for >> this. >> >> I am running a 2.6.21 SMP mips kernel and on some occasions the kernel >> halts on startup. This only happens at boot time, that is, once the >> system is running it never exhibits the problem. >> >> The problem occurs when trying to read the partitions from the SATA >> drive, on the first call to read_dev_sector(). As I understand it, the >> code finishes doing a sync_page() which starts an asynchronous I/O >> operation and sleeps until awaken by an interrupt generated by the >> SATA device. >> >> I have followed the code through until the call to ata_bmdma_start(), >> where it does: >> >> iowrite8(dmactl | ATA_DMA_START, ap->ioaddr.bmdma_addr + ATA_DMA_CMD); >> >> On a working case, the device interrupts and the flow continues. On a >> non working case, there is a delay of 5 or 6 seconds, and then a >> series of calls to sil_freeze(), ata_bmdma_error_handler() and >> ata_bmdma_stop(). >> >> I am about to delve into the ATA specs to try to understand this >> > > ATA spec. itself won't avail here, it doesn't cover host's DMA support. You > probably want to read the part concerning "PCI Compatibility and PCI-Native > Mode Bus Master Adapters" pf this document: > > http://www.t13.org/Documents/UploadedDocuments/project/d1510r1-Host-Adapter.pdf > >> interaction, but has anybody seen this behavior before? Please CC me >> on replies. >> > > Generally, DMA timeouts are seen quite frequently... > > MBR, Sergei > > > -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
