From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 1/2] ide: Add tx4939ide driver Date: Tue, 09 Sep 2008 21:08:14 +0400 Message-ID: <48C6AD7E.10005@ru.mvista.com> References: <20080910.010824.07456636.anemo@mba.ocn.ne.jp> <20080909174459.2aa9808a@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from gateway-1237.mvista.com ([63.81.120.155]:57065 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752518AbYIIRHk (ORCPT ); Tue, 9 Sep 2008 13:07:40 -0400 In-Reply-To: <20080909174459.2aa9808a@lxorguk.ukuu.org.uk> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Atsushi Nemoto Cc: Alan Cox , linux-mips@linux-mips.org, linux-ide@vger.kernel.org, Bartlomiej Zolnierkiewicz , ralf@linux-mips.org Hello. Alan Cox wrote: >>+#define TX4939IDE_readl(base, reg) \ >>+ __raw_readl((void __iomem *)((base) + TX4939IDE_REG32(reg))) >>+#define TX4939IDE_readw(base, reg) \ >>+ __raw_readw((void __iomem *)((base) + TX4939IDE_REG16(reg))) >>+#define TX4939IDE_readb(base, reg) \ >>+ __raw_readb((void __iomem *)((base) + TX4939IDE_REG8(reg))) >>+#define TX4939IDE_writel(val, base, reg) \ >>+ __raw_writel(val, (void __iomem *)((base) + TX4939IDE_REG32(reg))) >>+#define TX4939IDE_writew(val, base, reg) \ >>+ __raw_writew(val, (void __iomem *)((base) + TX4939IDE_REG16(reg))) >>+#define TX4939IDE_writeb(val, base, reg) \ >>+ __raw_writeb(val, (void __iomem *)((base) + TX4939IDE_REG8(reg))) > It's generally frowned upon to hide all the detail in macros, it is much > easier to read and understand the code if you don't do this. >>+#define TX4939IDE_BASE(hwif) ((hwif)->io_ports.data_addr & ~0xfff) > Why do you have void __iomem casts all over the write methods not in the > _BASE() method - that would let sparse do its job properly I don't get why there's need for & at all -- isn't IDE data register address always on 4K boundary? >>+ for (i = 0; i < MAX_DRIVES; i++) { >>+ if (drive != &hwif->drives[i] && > You don't actually need the first test. No, he does need it -- in order not to clamp the new PIO mode based on the previosly selected one. Although, one should call ide_get_paired_drive() ISO this loop. > This also appears wrong. In your > tests MW_DMA_0 is 'faster' than PIO4 but in fact MW_DMA_0 PIO timings are > *slower* than PIO4 so the mode is not in fact slower. I don't think it's about the DMA timings at all. Though indeed, MWDMA0/1 do (iff it's drive's max) implies slower max PIO mode than PIO4. >>+ case XFER_MW_DMA_2: >>+ case XFER_MW_DMA_1: >>+ case XFER_MW_DMA_0: >>+ case XFER_PIO_4: >>+ value |= 0x0400; >>+ break; > This looks odd according to the speed tables. Can you clarify what is > going on ? This apparently selects the command PIO timing safest for both drives but does this incorrectly -- the current DMA (or even PIO) mode shouldn't be a part of the equation. There are several examples how to do this including siimage.c and cs5535.c... MBR, Sergei