[Skiboot] [PATCH] capi: Enable channel tag streaming for PHB in CAPP mode

Stewart Smith stewart at linux.vnet.ibm.com
Tue Feb 13 19:27:20 AEDT 2018

Vaibhav Jain <vaibhav at linux.vnet.ibm.com> writes:
> We re-enable channel tag streaming for PHB in CAPP mode as without it
> PEC was waiting for cresp for each DMA write command before sending a
> new DMA write command on the Powerbus. This resulted in much lower DMA
> write performance than expected.
> The patch updates enable_capi_mode() to remove the masking of
> channel_streaming_en bit in PBCQ Hardware Configuration Register. Also
> does some re-factoring of the code that updates this register to use
> xscom_write_mask instead of xscom_read followed by a xscom_write.
> Cc: stable
> Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>


Since nobody is really paying attention to 5.9.x for any further stable
releases, I've not pulled this in there (and as I say this... there'll
be something that'll cause it).

But merged to master as of 328af10e1c113449198373fa5d9dbbf1b66ddd7e
Stewart Smith
OPAL Architect, IBM.

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