On Mon, Jan 16, 2012 at 6:39 PM, Kyungmin Park <kmpark@xxxxxxxxxxxxx> wrote: > On Mon, Jan 16, 2012 at 7:37 PM, S, Venkatraman <svenkatr@xxxxxx> wrote: >> On Fri, Jan 13, 2012 at 3:40 PM, Kyungmin Park <kmpark@xxxxxxxxxxxxx> wrote: >>> On 1/13/12, Chris Ball <cjb@xxxxxxxxxx> wrote: >>>> Hi, >>>> >>>> On Thu, Jan 12 2012, S, Venkatraman wrote: >>>>> On Wed, Dec 21, 2011 at 1:09 PM, Saugata Das <saugata.das@xxxxxxxxxxxxxx> >>>>> wrote: >>>>>> From: Saugata Das <saugata.das@xxxxxxxxxx> >>>>>> >>>>>> MMC-4.5 data tag feature will be used to store the file system >>>>>> meta-data in the >>>>>> tagged region of eMMC. This will improve the write and subsequent >>>>>> read transfer >>>>>> time for the meta data. >>>>>> >>>>>> Signed-off-by: Saugata Das <saugata.das@xxxxxxxxxx> >>>>> >>>>> I tested this on a device which supports a data tag unit size of 8K. >>>>> Tested-by: Venkatraman S <svenkatr@xxxxxx> >>>> >>>> Thanks for testing! I've pushed it to mmc-next. >>>> >>>>> Chris, >>>>> Can this go into 3.3 ? >>>> >>>> I think 3.4 would be better after a full round of linux-next testing, >>>> since this sounds like it could expose card-dependent quirks that could >>>> destroy filesystems. Better to be safe. >>> I'm afraid it that it's really required since some features. data tag, >>> context id, and packed command, are not mutual exclusive. so I hope to >>> make it select. I mean it's not measured the real performance gain >>> and/or other feature. so hope to enable/disable by platform data. >>> >>> How do you think? >>> >>> Thank you, >>> Kyungmin Park >> >> I don't understand your comment on them not being mutually exclusive. >> As it is, these are core features and they don't belong in platform data. >> Can you explain a bit more ? > To get the gain these features, data tag, context ID, it requires the > firmware support. > But currently there's no idea to support these feature at firmware. So > we can't get the valuable performance gain. But that's neither a kernel issue, nor is a 'regression'. At worst, the card should behave like a 4.41 standard card for an unoptimized firmware. The platform data is the wrong location to indicate what are essentially standards driven features. I am wondering already the need for CAPS2_BKOPS_SUPPORT and the like, when the feature has nothing to do with the host controller. > and now there's no data if it enables the both, data tag, packed > command or other combination, e.g., cache and so on. > > So I suggest make it enable/disable these features at platform data, > similarly support pre-defined op by MMC_CAP_CMD23. > and I saw the Saugata's active regards with Context ID. so it's also > make it configurable. > > Thank you, > Kyungmin Park -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
