On Sat, 2017-09-09 at 18:39 +0800, Ming Lei wrote: > - the issue is not suspend/resume only, it is about SCSI quiesce vs. > RQF_PREEMPT.
The only in-kernel user of the SCSI quiesce/resume functionality next to runtime power management I know of is the SPI transport, namely spi_dv_device(). Nobody has ever reported a hang in spi_dv_device() as far as I know. Since the number of users of the SCSI parallel transport is very small I propose to wait with fixing spi_dv_device() until someone shows that it is possible to trigger that hang. If we have to address a hang in spi_dv_device() I propose to address it in the same way as my patch series addresses power management requests, namely by letting previously submitted requests complete and by making blk_get_request() callers wait until the quiesced SCSI device has been resumed. > I don't see the issue above addressed by this patchset, so maybe > you are trying to fix another PM specific issue(not reported by > Oleksandr), I am just confused. That's correct - I'm only trying to address the PM issues. I will mention that explicitly when I repost this patch series. Bart.
