On Mon, 30 Mar 2009, Grant Grundler wrote: > Followup to "[PATCH 03/10] ide: destroy DMA mappings after ending DMA" > email on March 14th: > http://lkml.org/lkml/2009/3/14/17 > > No maintainer is listed for "Toshiba CELL Reference Set IDE" (BLK_DEV_CELLEB) > or tx4939ide.c in MAINTAINERS. I've CC'd "Ishizaki Kou" @Toshiba (Maintainer for > "Spidernet Network Driver for CELL") and linuxppc-dev list in the hope > someone else > would know or would be able to ACK this patch. tx49xx is MIPS, for Nemoto-san. > This patch: > o replaces "mask" variable in ide_dma_end() with #define. > o removes use of wmb() in ide-dma-sff.c and scc_pata.c. > o is not tested - I don't have (or want) the HW. > > I did NOT remove wmb() use in tx4939ide.c. tx4939ide.c __raw_writeb() > for MMIO transactions. __raw_writeb() does NOT guarantee memory > transaction ordering. > > tx4939ide also uses mmiowb(). AFAIK, mmiowb() only has an effect on > SGI IA64 NUMA machines. I'm not going to guess how this driver might work. > > Gmail is broken for sending patches (word wrap). My apologies. > I've attached the patch: diff-next-remove_wmb_from_ide-01.txt > > Patch is against linux-next tree: > git://git.kernel.org/pub/scm/linux/kernel/git/sfr/linux-next > > Signed-off-by: Grant Grundler <grundler@xxxxxxxxxx> [ attachment converted to inline ] > diff --git a/drivers/ide/ide-dma-sff.c b/drivers/ide/ide-dma-sff.c > index 16fc46e..e4cdf78 100644 > --- a/drivers/ide/ide-dma-sff.c > +++ b/drivers/ide/ide-dma-sff.c > @@ -277,8 +277,6 @@ void ide_dma_start(ide_drive_t *drive) > dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD); > outb(dma_cmd | ATA_DMA_START, hwif->dma_base + ATA_DMA_CMD); > } > - > - wmb(); > } > EXPORT_SYMBOL_GPL(ide_dma_start); > > @@ -286,7 +284,7 @@ EXPORT_SYMBOL_GPL(ide_dma_start); > int ide_dma_end(ide_drive_t *drive) > { > ide_hwif_t *hwif = drive->hwif; > - u8 dma_stat = 0, dma_cmd = 0, mask; > + u8 dma_stat = 0, dma_cmd = 0; > > /* stop DMA */ > if (hwif->host_flags & IDE_HFLAG_MMIO) { > @@ -304,11 +302,10 @@ int ide_dma_end(ide_drive_t *drive) > /* clear INTR & ERROR bits */ > ide_dma_sff_write_status(hwif, dma_stat | ATA_DMA_ERR | ATA_DMA_INTR); > > - wmb(); > +#define CHECK_DMA_MASK (ATA_DMA_ACTIVE | ATA_DMA_ERR | ATA_DMA_INTR) > > /* verify good DMA status */ > - mask = ATA_DMA_ACTIVE | ATA_DMA_ERR | ATA_DMA_INTR; > - if ((dma_stat & mask) != ATA_DMA_INTR) > + if ((dma_stat & CHECK_DMA_MASK) != ATA_DMA_INTR) > return 0x10 | dma_stat; > return 0; > } > diff --git a/drivers/ide/scc_pata.c b/drivers/ide/scc_pata.c > index 97f8e0e..dcbb299 100644 > --- a/drivers/ide/scc_pata.c > +++ b/drivers/ide/scc_pata.c > @@ -337,7 +337,6 @@ static void scc_dma_start(ide_drive_t *drive) > > /* start DMA */ > scc_ide_outb(dma_cmd | 1, hwif->dma_base); > - wmb(); > } > > static int __scc_dma_end(ide_drive_t *drive) > @@ -354,7 +353,6 @@ static int __scc_dma_end(ide_drive_t *drive) > /* clear the INTR & ERROR bits */ > scc_ide_outb(dma_stat | 6, hwif->dma_base + 4); > /* verify good DMA status */ > - wmb(); > return (dma_stat & 7) != 4 ? (0x10 | dma_stat) : 0; > } With kind regards, Geert Uytterhoeven Software Architect Sony Techsoft Centre Europe The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium Phone: +32 (0)2 700 8453 Fax: +32 (0)2 700 8622 E-mail: Geert.Uytterhoeven@xxxxxxxxxxx Internet: http://www.sony-europe.com/ A division of Sony Europe (Belgium) N.V. VAT BE 0413.825.160 · RPR Brussels Fortis · BIC GEBABEBB · IBAN BE41293037680010
