Hi Krzysztof, On 13 October 2015 at 09:13, Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> wrote: > > On 13.10.2015 12:08, Anand Moon wrote: > > Hi Krzysztof, > > > > On 13 October 2015 at 05:44, Krzysztof Kozlowski > > <k.kozlowski@xxxxxxxxxxx> wrote: > >> On 13.10.2015 00:32, Anand Moon wrote: > >>> Hi Krzysztof, > >>> > >>> On 12 October 2015 at 11:14, Krzysztof Kozlowski > >>> <k.kozlowski@xxxxxxxxxxx> wrote: > >>>> On 12.10.2015 00:46, Anand Moon wrote: > >>>>> Added support for UHS-I bus speed 50MB/s (SDR50, DDR50) 104MB/s (SDR104) > >>>> > >>>> This description is not entirely correct. The MMC driver already > >>>> supports these UHS speeds (you did not any code) so you rather enabled > >>>> it (description of bindings says "is supported"). > >>>> > >>>> You mentioned DDR50 but I don't see respective property below. > >>>> > >>>> How do you know that these modes are really supported? I don't know. Can > >>>> you convince me? > >>> > >>> Setting this DDR50 capability give me this error. That's the reason to > >>> drop this capability. > >> > >> But you mentioned it in commit message! "Added support for UHS-I ... > >> (DDR50)" > >> > >> In the same time dropping DDR50 is not an sufficient proof that "SDR50 > >> and SDR104 are really supported". > >> > > > > These changes are related to the microSD card capabilities. > > So SDR50 have better frequency over DDR50. On the same Sandisk card. > > > > When the card select the capability for DDR50 > > --------------------------------------------------- > > [ 4.001477] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot > > req 50000000Hz, actual 50000000HZ div = 0) > > [ 4.001604] mmc1: new ultra high speed DDR50 SDHC card at address aaaa > > [ 4.004505] mmcblk0: mmc1:aaaa SL32G 29.7 GiB > > [ 4.009179] mmcblk0: error -110 sending status command, retrying > > [ 4.009271] mmcblk0: error -115 sending stop command, original cmd > > response 0x900, card status 0x900 > > [ 4.009275] mmcblk0: error -84 transferring data, sector 0, nr 8, > > cmd response 0x900, card status 0x0 > > [ 4.025563] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot > > req 400000Hz, actual 396825HZ div = 63) > > [ 4.067770] Console: switching to colour frame buffer device 274x77 > > [ 4.098782] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot > > req 50000000Hz, actual 50000000HZ div = 0) > > [ 4.099692] mmc1: tried to reset card > > [ 4.101332] mmcblk0: p1 p2 > > > > > > When the card select the capability for SDR50 > > --------------------------------------------------------------------------------- > > [ 2.439806] mmc_host mmc1: Bus speed (slot 0) = 100000000Hz (slot req > > 100000000Hz, actual 100000000HZ div = 0) > > [ 2.449729] mmc1: new ultra high speed SDR50 SDHC card at address aaaa > > [ 2.455984] mmcblk0: mmc1:aaaa SL32G 29.7 GiB > > [ 2.461743] mmcblk0: p1 p2 > > > > Which will relate to better read/write speed. > > Which is not an answer to my question. To none of my previous questions. > Basically UHS-I capability (sd-uhs-sdr12, sd-uhs-sdr25, sd-uhs-sdr50, sd-uhs-sdr104) help tune speed supported for mmc I have tired to compare the speed on high speed UHS-I vs ultra high speed UHS-I using izone utility. [ 2.572469] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req 50000000Hz, actual 50000000HZ div = 0) [ 2.572609] mmc1: new high speed SDHC card at address aaaa Command line used: ./iozone -L64 -S32 -azecwI -+n -r4k -r64k -r128k -s10M -i0 -i1 -i2 -f datafile -Rb out.xls Output is in kBytes/sec Time Resolution = 0.000001 seconds. Processor cache size set to 32 kBytes. Processor cache line size set to 64 bytes. File stride size set to 17 * record size. random random bkwd record stride kB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread 10240 4 1631 0 6556 0 5538 982 10240 64 8828 0 18897 0 17994 303 10240 128 6269 0 20670 0 20128 1096 --------------------------------------------------------------------------------------------------------- [ 2.613761] mmc_host mmc1: Bus speed (slot 0) = 100000000Hz (slot req 100000000Hz, actual 100000000HZ div = 0) [ 2.623573] mmc1: new ultra high speed SDR50 SDHC card at address aaaa Command line used: ./iozone -L64 -S32 -azecwI -+n -r4k -r64k -r128k -s10M -i0 -i1 -i2 -f datafile -Rb out.xls Output is in kBytes/sec Time Resolution = 0.000001 seconds. Processor cache size set to 32 kBytes. Processor cache line size set to 64 bytes. File stride size set to 17 * record size. random random bkwd record stride kB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread 10240 4 1809 0 7507 0 5233 859 10240 64 11622 0 31250 0 28072 516 10240 128 4320 0 34417 0 32509 1148 My observation is that their slight increase in read/write operation. Hope I have tried to answer you query. If I am wrong please let me know. -Anand Moon > > Best regards, > Krzysztof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html