From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: UDMA with CS5530 using IBM Netvista N2200 (8363) Date: Wed, 10 Sep 2008 18:55:40 +0400 Message-ID: <48C7DFEC.1090109@ru.mvista.com> References: <48C45BEF.5090502@gmail.com> <20080908094332.7b021b4e@lxorguk.ukuu.org.uk> <48C5BD49.6090204@gmail.com> <20080909115248.580eba78@lxorguk.ukuu.org.uk> <48C70313.6080704@gmail.com> <20080910093840.0fc9df68@the-village.bc.nu> <43e9b8530809100614t616154caldb32c4207b5b44ad@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from homer.mvista.com ([63.81.120.155]:13103 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751487AbYIJOzD (ORCPT ); Wed, 10 Sep 2008 10:55:03 -0400 In-Reply-To: <43e9b8530809100614t616154caldb32c4207b5b44ad@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Antonio Martins Cc: linux-ide@vger.kernel.org Hello. Antonio Martins wrote: >>>Booting with CONFIG_BLK_DEV_CS5530=n and CONFIG_PATA_CS5530=y and >>>libdata_dma_mask=0 >>>kernel 2.6.24.7: >>>... >>>ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx >>>Driver 'sd' needs updating - please use bus_type methods >>>scsi0: pata_cs5530 >>>scsi1: pata_cs5530 >>>ata1: PATA max UDMA/33 cmd 0x1f0 ctl 0x3f6 bmdma 0xfc00 irq 14 >>>ata2: PATA max UDMA/33 cmd 0x170 ctl 0x376 bmdma 0xfc08 irq 15 >>>ata1.00: ATA-5: SILICON POWER, 2.0, mas UDMA/66 >>>ata1.00: 2000880 sectors, multi 1: LBA >>>ata1.00: configured for PIO4 >>>scsi 0:0:0:0: Direct-Access ATA SILICON POWER 2.0 PQ: 0 ANSI: 5 >>>sd 0:0:0:0: [sda] 2000880 512-byte hardware sectors (1024 MB) >>>sd 0:0:0:0: [sda] Write Protect is off >>>sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA >>>sd 0:0:0:0: [sda] 2000880 512-byte hardware sectors (1024 MB) >>>sd 0:0:0:0: [sda] Write Protect is off >>>sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA >>> sda: sda1 >>And now it all works nicely >>>Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) >>>So PIO4 is now working. Great. But i am stuck with the root device. >>I would suggest posting to linux-kernel on that and talking to H Peter >>Anvin about possible ways to get a real boot loader on the box. > So regarding DMA, Netvista 8363 has this limitation, and there is no > DMA or UDMA mode that we can successfully enable. The only way to > force PIO4, is changing directly in the source code. > If kernel parameters were supported, we would be able to use some "idebus" > parameter. Are these statements correct? There's "libata.dma=" option (if you can pass it), set it to 0 and DMA won't ever be used. Note that the "old" IDE code also has the parameter controlling DMA usage (even per drive) -- look for "nodma" in Documentation/ide/ide.txt. MBR, Sergei