Andrei Warkentin wrote: > On Fri, May 20, 2011 at 1:49 AM, Andrei Warkentin <andreiw@xxxxxxxxxxxx> wrote: >> On Thu, May 19, 2011 at 11:38 PM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote: >>> Hi Andrei, >>> >>> Andrei Warkentin wrote: >>>> On Wed, May 18, 2011 at 9:37 PM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote: >>>>> Hi Andrei >>>>> >>>>> Andrei Warkentin wrote: >>>>>> CMD23-prefixed instead of open-ended multiblock transfers >>>>>> have a performance advantage on some MMC cards. >>>>>> >>>>> you mentioned about "some MMC cards". >>>>> Conversely, that means the some card didn't have a performance advantage? >>>>> >>>>> Did you find the performance advantage? >>>>> if you found the advantage and you can tell me, >>>>> i want to know what do you have the some MMC cards.. >>>>> >>>> I've tested this on a Sandisk eMMC where I saw as good as >>>> a 50% improvement on writes (30% real-life use cases). This was a >>>> SEM32G 4.3+ part. >>> Can you tell me your environment? buswidth, AP information, benchmark etc.. >>> And if you have the performance result's data, can you share them? >>> >> This was on an SDHCI controller (hence the patch...) on a Tegra >> 2-based system. I was measuring >> throughput on reads and writes (obviously without block cache, >> filesystem, etc) to an eMMC card, 8 bits. >> >> Tested both with my tool (https://github.com/andreiw/superalign) and >> an sqllite-based test. >> >> I'm attaching the data I have. >> >> A >> > > Additionally, CMD23 use is a requirement for SDXC cards (Arindam can > comment on that), as well as for MMC reliable writes and eMMC 4.5-spec > features (Yunpeng Gao can comment on that). > > These patches allow CMD23 use. They do involve a some changes to host > controller because of interaction with CMD12, as well as Auto-CMD12 > and Auto-CMD23 features. I can definitely consult you if you need help > implementing CMD23 support for whatever controller you develop for. > I used two host-controller (sdhci and dw_mmc). you implemented them in sdhci. I applied your patch then tested CMD23...but i didn't applied auto-CMD23. I known that auto-CMD23 supported at SD3.0..right? My controller is supported SD2.0.. If you can consult me, too much helpful to me.. Regards, Jaehoon Chung -- 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
