Date: Fri, 29 Jan 2016 08:43:45 +0100 From: Norbert Koch <nkoch@demig.de> To: <freebsd-hackers@FreeBSD.org> Subject: Re: impossible to set pata dma mode? Message-ID: <56AB1831.2070907@demig.de> In-Reply-To: <1454001217.1275.19.camel@freebsd.org> References: <56A9D502.7010809@demig.de> <1453995911.1275.14.camel@freebsd.org> <56AA42CF.10408@demig.de> <1454001217.1275.19.camel@freebsd.org>
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Am 28.01.2016 um 18:13 schrieb Ian Lepore: > On Thu, 2016-01-28 at 17:33 +0100, Norbert Koch wrote: >> Am 28.01.2016 um 16:45 schrieb Ian Lepore: >> >> >> Thanks Ian, I know that I can configure this using >> boot hints. >> >> I am having a rather special situation where I need to >> change these settings after boot. It has to do with >> pxe booting different FreeBSD versions using an >> outdated grub which only allows to directly load >> a kernel without specifying boot parameters. >> >> Obviously I can help myself with a modified >> camcontrol. But I am still curious what the >> reason for the limitation might be. >> >> > I'll have to leave the cam-related questions for the cam gurus. > > Do you have a custom kernel for these systems? If so, you can > configure tunables by compiling a static environment into the kernel > using the 'env' argument described in config(5). I recently committed > changes that fix the env directive so that it works on all > architectures now. Still maybe not what you need, but worth > mentioning. > > -- Ian Yes, you are right. I could build a custom kernel with "hints my.hints" or "env my.env", having a line hint.ata.0.mode="WDMA2". Thanks. > >>> On Thu, 2016-01-28 at 09:44 +0100, Norbert Koch wrote: >>>> Hello. >>>> >>>> I have to reduce dma mode from udma to wdma2 >>>> for a flash device. >>>> >>>> In the past this was easy using atacontrol >>>> but, afaiks it seems to be impossible using camcontrol. >>>> >>>> camcontrol negotiate ada0 -M wdma >>>> ...You can only modify user parameters >>>> >>>> camcontrol negotiate ada0 -NM wdma >>>> Works, but I see no way how those user >>>> parameters become active parameters as the >>>> driver only reads then in attach as far as >>>> I can see. >>>> >>>> It seems like the ata driver's interface >>>> allows to change the current settings >>>> (XPT_SET_TRAN_SETTINGS/CTS_TYPE_CURRENT_SETTINGS) >>>> so, why is camcontrol so restrictive? >>>> >>>> Thank you, >>>> Norbert Koch >>> I don't know about changing it on the fly with camcontrol (I've >>> never >>> done that), but you can configure it at boot time with a tunable in >>> loader.conf of the form >>> >>> dev.ada.0.mode="modestr" >>> >>> Where modestr is one of these (from dev/ata/ata-all.c): >>> >>> if (!strcasecmp(str, "PIO0")) return (ATA_PIO0); >>> if (!strcasecmp(str, "PIO1")) return (ATA_PIO1); >>> if (!strcasecmp(str, "PIO2")) return (ATA_PIO2); >>> if (!strcasecmp(str, "PIO3")) return (ATA_PIO3); >>> if (!strcasecmp(str, "PIO4")) return (ATA_PIO4); >>> if (!strcasecmp(str, "WDMA0")) return (ATA_WDMA0); >>> if (!strcasecmp(str, "WDMA1")) return (ATA_WDMA1); >>> if (!strcasecmp(str, "WDMA2")) return (ATA_WDMA2); >>> if (!strcasecmp(str, "UDMA0")) return (ATA_UDMA0); >>> if (!strcasecmp(str, "UDMA16")) return (ATA_UDMA0); >>> if (!strcasecmp(str, "UDMA1")) return (ATA_UDMA1); >>> if (!strcasecmp(str, "UDMA25")) return (ATA_UDMA1); >>> if (!strcasecmp(str, "UDMA2")) return (ATA_UDMA2); >>> if (!strcasecmp(str, "UDMA33")) return (ATA_UDMA2); >>> if (!strcasecmp(str, "UDMA3")) return (ATA_UDMA3); >>> if (!strcasecmp(str, "UDMA44")) return (ATA_UDMA3); >>> if (!strcasecmp(str, "UDMA4")) return (ATA_UDMA4); >>> if (!strcasecmp(str, "UDMA66")) return (ATA_UDMA4); >>> if (!strcasecmp(str, "UDMA5")) return (ATA_UDMA5); >>> if (!strcasecmp(str, "UDMA100")) return (ATA_UDMA5); >>> if (!strcasecmp(str, "UDMA6")) return (ATA_UDMA6); >>> if (!strcasecmp(str, "UDMA133")) return (ATA_UDMA6); >>> >>> -- Ian >> -- Dipl.-Ing. Norbert Koch Entwicklung Prozessregler
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