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. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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