On Tue, Oct 8, 2013 at 9:58 AM, Ganbold Tsagaankhuu <ganbold_at_gmail.com>wrote: > Zbigniew, > > > On Tue, Oct 8, 2013 at 3:54 AM, Zbigniew Bodek <zbb_at_freebsd.org> wrote: > >> Hello. >> >> I would like to present a patch for ns8250 serial that I would like to >> commit in the near future (if there are no objections). >> >> The patch is fixing newest DesignWare UART with busy detection. >> During frequency divisors configuration when UART is busy transferring or >> receiving data, line control register manipulation will not take effect. >> Therefore, we will not set divisor latch access bit and we will corrupt >> LCR >> instead of configuring divisors. >> It is necessary to wait until UART finishes all transfers to proceed with >> the configuration. >> >> This was detected on Armada XP as UART fails on this issue 100/100 >> attempts. >> The patch was tested by kevlo_at_ and me and it works on our Armada XP - >> based >> systems. >> >> Please send your comment or remarks if there are any. >> > > I'm trying your patch on r254983. > Tried on 2 boards (Cubieboard2 (Allwinner A20 SoC - dual Cortex A7) and > Radxa Rock (Rockchip RK3188 - Quad Cortex A9)). Both seem to have some sort > of DesignWare uart. > > 1. It works fine on Cubieboard2. Uart dmesg is like: > > uart0: <16750 or compatible> mem 0x1c28000-0x1c283ff irq 33 on simplebus0 > > uart0: console (115200,n,8,1) > > 2. No any printing on screen in case of Radxa Rock. Without your patch > uart dmesg is like: > > uart0: <16650 or compatible> mem 0x20064000-0x200643ff irq 68 on > simplebus0 > uart0: console (115200,n,8,1) > > In case of RK3188 SoC, it seems booting FreeBSD kernel seems very fragile, > not sure yet what is causing the problem. > Even with stock ns8250 some version later than r254983 didn't show/print > anything on serial console few days ago. > Only thing so far I know is this r254983 (with some patch) works in my > case on RK3188 SoC based board. > Zbigniew, Just tried again your patch on RK30xx board. I was able to see boot messages on screen. This uart detected as: ... uart0: <16650 or compatible> mem 0x20064000-0x200643ff irq 68 on simplebus0 uart0: console (115200,n,8,1) uart0: fast interrupt ... Can you show me your uart detection log? It seems this DW uart of RK30xx is different than DW uart of A10/A20. Boot simply stops printing "start_init: trying /sbin/init". thanks, Ganbold > > thanks, > > Ganbold > > > > >> >> Best regards >> Zbigniew Bodek >> >> _______________________________________________ >> freebsd-current_at_freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-current >> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org >> " >> > >Received on Wed Oct 09 2013 - 01:46:06 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:40:42 UTC