Date: Thu, 28 Jan 2016 17:33:19 +0100 From: Norbert Koch <nkoch@demig.de> To: <freebsd-hackers@FreeBSD.org> Subject: Re: impossible to set pata dma mode? Message-ID: <56AA42CF.10408@demig.de> In-Reply-To: <1453995911.1275.14.camel@freebsd.org> References: <56A9D502.7010809@demig.de> <1453995911.1275.14.camel@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
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 It has to do with pxe booting different FreeBSD versions using an outdated grub which only allows to directly load a kernel without specifying boot parameters.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. > 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?56AA42CF.10408>