Shaohio --
Once again, thanks for the reply.
Xie Shaohui-B21989 <b21...@freescale.com> writes:
> it seems [recovery or lack of recovery is] not due to speed limiting
> code, 1.5Gbps is still used to recover link.
Right, I noticed this in my later email on this topic.
> for the speed limit issue, I checked 3.4.rc7 kernel, there seems a
> place can be used to limit the speed for 8315:
>
> if (!of_device_is_compatible(ofdev->dev.of_node, "fsl,mpc8315-sata")) {
> temp = ioread32(csr_base + TRANSCFG);
> temp = temp & 0xffffffe0;
> iowrite32(temp | TRANSCFG_RX_WATER_MARK, csr_base + TRANSCFG);
> } else {
> /* the speed limitation code for 8315 may can be put here.
> * just move the original code which wrapped by "#ifdef
> CONFIG_MPC8315_DS" here.
> * please let me know if you will give a try. */
> }
It's not clear that all uses of the MPC8315 SATA controller have this
problem. It obviously occured on the 8315DS, but apparently that
board never made it to production; it might or might not happen on the
8315ERDB; and it clearly happens on my vendor's board.
Given this lack of knowledge, Scott Wood was very hesitant to
implement any far-reaching changes, because we could not pin down
exactly what had to be tested.
My original patch:
http://article.gmane.org/gmane.linux.ports.ppc.embedded/58710
did the speed limiting directly in the sata_fsl code; Jeff Garzik
mentioned that there was some existing infrastructure for this, and I
inferred that he would prefer that I use it.
So that's what my final patch does, and it's keyed off a single OF
value.
There's a small chance that I'll have the opportunity to move the
project to 3.9 (especially if that release gets declared
long-term-stable). Even then, I unfortunately won't have the
bandwidth to pursue getting any of these approaches into mainline.
The best I can do is get them onto the lists so that others might be
able to benefit later.
Either way, thanks again. I'll try to put together a package for my
vendor to test with; once I have demonstrated that there is a problem
with their hardware, they have been gracious about accepting that
result and pursuing it with Freescale if necessary.
Thanks again for your help!
Best regards,
Anthony Foiani
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