On Wed, 2010-02-24 at 21:13 +0000, Benjamin Herrenschmidt wrote: > On Wed, 2010-02-24 at 11:19 -0500, Alan Stern wrote: > > > It is but I'm not confident the responsibility for doing that cleanup > > > is at the HCD level. That would impact a lot of HCD activities that > > > don't need such flushing since the use of the page is purely in-kernel. > > > > That's right. The HCD merely puts data wherever it's told to. It > > doesn't know whether the destination is in the page cache, in > > userspace, or anywhere else. The same is true for usb-storage. > > I'm surprised that usb-storage has an issue here. It shouldn't afaik, > since it's just a SCSI driver (or not anymore ?) and the BIO or > filesystems handle things there no ? I haven't seen a single call to > flush_dcache_page() in any of drivers/scsi, drivers/ata or drivers/ide > when I looked... The BIO or filesystem code don't call flush_dcache_page() either (well some do like cramfs or jffs but they decompress the data received from the block device). -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
