[Skiboot] [PATCH skiboot] npu2: Advertise correct TCE page size

Stewart Smith stewart at linux.ibm.com
Wed Dec 12 12:18:38 AEDT 2018

Alexey Kardashevskiy <aik at ozlabs.ru> writes:
> On 11/12/2018 17:30, Stewart Smith wrote:
>> Alexey Kardashevskiy <aik at ozlabs.ru> writes:
>>> The P9 NPU workbook says that only 4K/64K/16M/256M page size are supported
>>> and in fact npu2_map_pe_dma_window() supports just these but in absence of
>>> the "ibm,supported-tce-sizes" property Linux assumes the default P9 PHB4
>>> page sizes - 4K/64K/2M/1G - so when Linux tries 2M/1G TCEs, we get lots of
>>> "Unexpected TCE size" from npu2_tce_kill().
>>> This advertises TCE page sizes so Linux could handle it correctly, i.e.
>>> fall back to 4K/64K TCEs.
>> Merged to master as of 003ccd5775161d352c53cac3d00c6283eb036ffc - should
>> this also go to stable?
> The userspace can trigger those "Unexpected TCE size" messages a lot, is
> this a good enough reason for stable?

Probably - annoying messages are a bug.

Stewart Smith
OPAL Architect, IBM.

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