Re: Issues with SIS 964 chipset on SATA
Gary Poppitz wrote: We tracked down a problem with the 964 chipset with a 0x180 ID code that may save someone on the list some time. The chip will only transfer multiples of 4 bytes. Anything else will cause it to hang. After further research, this is popping up on a number of chips (and worked around in several vendor drivers). It looks like I will need to do a workaround for all SATA ATAPI devices: if the transfer is not a multiple of 4 bytes, pad it with an DMA 1-3 byte DMA segment. Jeff - To unsubscribe from this list: send the line unsubscribe linux-ide in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Issues with SIS 964 chipset on SATA
Mark Lord wrote: Jens Axboe wrote: It looks like I will need to do a workaround for all SATA ATAPI devices: if the transfer is not a multiple of 4 bytes, pad it with an DMA 1-3 byte DMA segment. Yup, that requirement has existed on most of the hardware I've done drivers for, both SATA and a lot of PATA chips too. PATA too? Interesting... Jeff - To unsubscribe from this list: send the line unsubscribe linux-ide in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Issues with SIS 964 chipset on SATA
Jens Axboe wrote: On Thu, Feb 17 2005, Jeff Garzik wrote: It looks like I will need to do a workaround for all SATA ATAPI devices: if the transfer is not a multiple of 4 bytes, pad it with an DMA 1-3 byte DMA segment. Yeah we definitely need something like that. The optimal solution is to make sure that all requests are fed through the bounce logic like fs requests. Could you elaborate? I'm not sure I follow. I hope you're not suggesting leaking 1-3 bytes of random memory, past the end of the request, into the DMA stream? Jeff - To unsubscribe from this list: send the line unsubscribe linux-ide in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Issues with SIS 964 chipset on SATA
Gary Poppitz wrote: We tracked down a problem with the 964 chipset with a 0x180 ID code that may save someone on the list some time. The chip will only transfer multiples of 4 bytes. Anything else will cause it to hang. Interesting, either ULi or SiS set me a needs-to-be-cleaned-up-a-lot fix for this. SATA transport is dword-based, so this is not surprising. For the SIS (or ULi, I forget) controller, and perhaps others, a workaround needs to be applied. Suggestions/patches welcome. We may want to guarantee _DMA_ of 4-byte-aligned chunks, but still only reflect the true amount in ATAPI CDB. Jeff - To unsubscribe from this list: send the line unsubscribe linux-ide in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
