USB 2.0 Re: [maemo-developers] speeding up MMC (with success)
Koen Kooi wrote: Frantisek Dufka schreef: Yet when usb cable is inserted kernel says something about full speed config. Unfortunately full speed is 12Mbps USB 1.1 speed. USB 2.0 is called high speed. usb 2.0 high speed = 12Mbps usb 2.0 full speed = 480MBps welcome to usb marketing speak :( Are you sure? I haven't come across this meaning yet. http://www.everythingusb.com/usb2/faq.htm http://www.linux-usb.org/usb2.html But anyway in kernel full speed realy means 12Mbps. Looks like g_file_storage can handle USB 2.0 (CONFIG_USB_GADGET_DUALSPEED) but it is not enabled. It looks like the host mode is only 1.1 (there is only ohci-omap, not ehci) but can at least the client/OTG mode do USB 2.0? Or is 'USB 2.0 device mode for PC connectivity' here http://europe.nokia.com/A4145105 a mistake? Frantisek ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: USB 2.0 Re: [maemo-developers] speeding up MMC (with success)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Frantisek Dufka schreef: Koen Kooi wrote: Frantisek Dufka schreef: Yet when usb cable is inserted kernel says something about full speed config. Unfortunately full speed is 12Mbps USB 1.1 speed. USB 2.0 is called high speed. usb 2.0 high speed = 12Mbps usb 2.0 full speed = 480MBps welcome to usb marketing speak :( Are you sure? I haven't come across this meaning yet. http://www.everythingusb.com/usb2/faq.htm http://www.linux-usb.org/usb2.html But anyway in kernel full speed realy means 12Mbps. Looks like g_file_storage can handle USB 2.0 (CONFIG_USB_GADGET_DUALSPEED) but it is not enabled. It looks like the host mode is only 1.1 (there is only ohci-omap, not ehci) but can at least the client/OTG mode do USB 2.0? Or is 'USB 2.0 device mode for PC connectivity' here http://europe.nokia.com/A4145105 a mistake? You can retroactively label usb 1.1 devices '2.0' and the pxa270 can only do 12Mbit regardless of what intel's marketing department labels it. regards, Koen -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (Darwin) iD8DBQFFIMZCMkyGM64RGpERAiwQAJ9HMCHJAJhgWNlGPK2uSM/xdQ4qAACfZgHx 4dRda2QP9CSBWxDVZDEQqs8= =J9Sj -END PGP SIGNATURE- ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: USB 2.0 Re: [maemo-developers] speeding up MMC (with success)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Koen Kooi schreef: Frantisek Dufka schreef: Koen Kooi wrote: Frantisek Dufka schreef: Yet when usb cable is inserted kernel says something about full speed config. Unfortunately full speed is 12Mbps USB 1.1 speed. USB 2.0 is called high speed. usb 2.0 high speed = 12Mbps usb 2.0 full speed = 480MBps welcome to usb marketing speak :( Are you sure? I haven't come across this meaning yet. http://www.everythingusb.com/usb2/faq.htm http://www.linux-usb.org/usb2.html But anyway in kernel full speed realy means 12Mbps. Looks like g_file_storage can handle USB 2.0 (CONFIG_USB_GADGET_DUALSPEED) but it is not enabled. It looks like the host mode is only 1.1 (there is only ohci-omap, not ehci) but can at least the client/OTG mode do USB 2.0? Or is 'USB 2.0 device mode for PC connectivity' here http://europe.nokia.com/A4145105 a mistake? You can retroactively label usb 1.1 devices '2.0' and the pxa270 can only do 12Mbit regardless of what intel's marketing department labels it. And by the looks of it the omap1710 as well :( -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (Darwin) iD8DBQFFIMZ+MkyGM64RGpERAtQ7AKCAB3G2QJhXpTCRMWiZ0Pgd4jNH9ACgqqDO NIZPq3L0XvtoaYyria/Vw+I= =K/DX -END PGP SIGNATURE- ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: USB 2.0 Re: [maemo-developers] speeding up MMC (with success)
Koen Kooi wrote: And by the looks of it the omap1710 as well :( Yes, found it - drivers/usb/gadget/omap_udc.c * omap_udc.c -- for OMAP full speed udc; most chips support OTG. No word about high speed. Looks like high speed UDC is rare thing. Found only this http://lists-archives.org/linux-usb-devel/12023-musb_hdrc-high-speed-otg-controller-driver.html I hope in will be in next nokia tablet together with OMAP 2430 and two SD/MMC slots :-) Frantisek ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] speeding up MMC (with success)
Hi! I tried your kernel with my 1GB extremetech and 2GB Kingston. No problems so far and twice the speed (will try 4x later today). Thanks for this free and very much needed hardware-upgrade, this will certainly become of even greater value when we will be able to use the mmc as root :-) Regards Sascha ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] speeding up MMC (with success)
Sascha Heid wrote: Hi! I tried your kernel with my 1GB extremetech and 2GB Kingston. No problems so far and twice the speed (will try 4x later today). Sounds good :-) this will certainly become of even greater value when we will be able to use the mmc as root :-) Yes, unfortunately current USB mass storage functionality seems to use only USB 1 speed so transfer over USB still has ~800KB/s limit. I wonder why USB 2.0 is not used. It is mentioned in N770 specs http://europe.nokia.com/A4145105 and OMAP 1710 should support USB OTG (which is IMO superset of USB 2.0 specifications). Yet when usb cable is inserted kernel says something about full speed config. Unfortunately full speed is 12Mbps USB 1.1 speed. USB 2.0 is called high speed. But at least scp or ftp over wi-fi to card should be a bit faster now. Otherwise it is not very useful unless you have lots of data on MMC or boot from it (which I do). Frantisek ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] speeding up MMC (with success)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Frantisek Dufka schreef: Yes, unfortunately current USB mass storage functionality seems to use only USB 1 speed so transfer over USB still has ~800KB/s limit. I wonder why USB 2.0 is not used. It is mentioned in N770 specs http://europe.nokia.com/A4145105 and OMAP 1710 should support USB OTG (which is IMO superset of USB 2.0 specifications). Yet when usb cable is inserted kernel says something about full speed config. Unfortunately full speed is 12Mbps USB 1.1 speed. USB 2.0 is called high speed. usb 2.0 high speed = 12Mbps usb 2.0 full speed = 480MBps welcome to usb marketing speak :( regards, Koen -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (Darwin) iD8DBQFFH68oMkyGM64RGpERAtt5AJ9mVQK4dGBIWtCK+C6S+iJ3wiaBlwCfdLqi AFr5tB9rjCHJi7/L0oUYgLI= =50Q/ -END PGP SIGNATURE- ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
[maemo-developers] speeding up MMC (with success)
Hello, recently I bought 2GB Kingston MMCmobile card and was a bit frustrated by N770 mmc slot speed. Basically any card inserted into N770 has speed ~1.3MB/s. I digged a bit in kernel sources and googled for MMC specs and discovered this: - maximum legacy MMC bus clock speed is 20Mhz - MMC v4 specification adds faster bus speed - 26 and 52Mhz, 13 pin interface and 4 and 8 bit data bus width (legacy = 1 bit) - TI OMAP mmc controller inside N770 uses 48Mhz reference clock and uses integer divider for reducing the speed to 24,16,12,... - connector inside N770 has only 7 pins (maybe 6) so only 1 bit data transfers are possible There is code in mmc driver which tries to determine proper speed that card reports it can handle. Then the omap mmc driver computes the divider. Fastest divider for 20Mhz bus speed should be 3 (as described in spru765a.pdf) which means 16Mhz (24 is too much). But there is strange line in omap mmc driver which then increases divider by one. So in reality it looks like in the name of maximum compatibility the divider is finally set to 4 so the clock is set to 12Mhz (= up to 1.5MB/s speed). When commenting out line 'dsor++;' in drivers/mmc/omap.c the bus speed is set to 16Mhz and speed jumps to ~1.7MB/s. Unfortunately the 64MB MMC card included with N770 stops working. I'm not sure this is kernel bug or the card reports wrong speed but it certainly explains why the speed is reduced in official kernel. Luckily my Sandisk 1GB RS-MMC has no problems with 16Mhz (as should any modern MMC card rated for 20Mhz bus). Then I found this patch http://marc.theaimsgroup.com/?l=linux-kernelm=114453090518554w=2 Unfortunately 4bit data transfers are not possible unless one wants to add those 2 or 3 pins for SD card (and also MMCplus) compatibility to the slot, but switching to higher speed works. 26Mhz exactly is not possible due to 48Mhz clock but 24Mhz runs just fine with my Kingston 2GB (as it should, specs say 0-26Mhz) and speed jumps to ~2.6MB/s (i.e. twice the original speed) With this speed system boots noticeably faster from MMC than from internal flash - boot progress bar finishes at 3/4 and application startup feels a bit faster. Even the old speed was comparable to flash speed (since jffs2 uses compression which slows I/O down and hogs CPU) but now MMC card is clear winner :-) Also newer cards should handle 52Mhz too. They report it in EXT_CSD register. So far there is no proper code in kernel to check this but when hardcoding 5200 to http://intr.overt.org/diff.cgi/diffs/mmcv4.diff and bumping up max omap mmc driver speed from 24Mhz to 48Mhz it looks like my Kingston 2gb MMCplus runs just fine with divider set to 1 = 48Mhz bus clock speed and data transfer speed goes to ~5MB/s. With this speed boot progress bar stops slightly after 1/2. So far the stability looks fine (same as with old speed). I have set system to boot from MMC, have swap on partition 1 and so far it is OK. I'm not sure TI supports 48Mhz for its MMC controller but I didn't found any limit mentioned in the docs and divider 1 seems to work fine. Also I hope the Kingston card really supports 52Mhz (or it should stop responding completely as defined by specs) so I hope I am not 'overclocking' anything. Hardcoding to 5200 is of course wrong and will fail with other cards, but 2600 is OK. Every MMCplus card must support 26Mhz bus clock speed. If anyone wants to test kernel with those changes it is here http:// fanoush.webpark.cz/maemo/zimage-su-18-200625-2gb-mmcplus26mhz.zip Make sure you first load and boot it without flashing (flasher -l -b). I did not try this specific kernel as for easy hacking I'm using different kernel with mmc drivers as modules (needs adding to initfs and linuxrc script). Also make sure you don't mind killing your device or MMC card or losing some data. It works for me for few days but of course YMMV. For 52Mhz speed please hack and compile kernel yourself :-) you can test card speed like this Nokia770-26:~# time dd if=/dev/mmcblk0 of=/dev/null bs=8192 count=10240 10240+0 records in 10240+0 records out real0m 15.90s user0m 0.02s sys 0m 2.33s 80MB in 16 seconds, not bad :-) Frantisek ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
