From 2fc37adba0fb05760b8635c6706773af828ccf3c Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Tue, 7 Apr 2009 19:18:32 -0400 Subject: [PATCH] [libata] sata_sil: disable DMA engine in sil_freeze() We must disable the DMA engine before accessing taskfile registers. Signed-off-by: Jeff Garzik --- drivers/ata/sata_sil.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/ata/sata_sil.c b/drivers/ata/sata_sil.c index 35bd5cc7f285..3cb69d5fb817 100644 --- a/drivers/ata/sata_sil.c +++ b/drivers/ata/sata_sil.c @@ -565,6 +565,19 @@ static void sil_freeze(struct ata_port *ap) tmp |= SIL_MASK_IDE0_INT << ap->port_no; writel(tmp, mmio_base + SIL_SYSCFG); readl(mmio_base + SIL_SYSCFG); /* flush */ + + /* Ensure DMA_ENABLE is off. + * + * This is because the controller will not give us access to the + * taskfile registers while a DMA is in progress + */ + iowrite8(ioread8(ap->ioaddr.bmdma_addr) & ~SIL_DMA_ENABLE, + ap->ioaddr.bmdma_addr); + + /* According to ata_bmdma_stop, an HDMA transition requires + * on PIO cycle. But we can't read a taskfile register. + */ + ioread8(ap->ioaddr.bmdma_addr); } static void sil_thaw(struct ata_port *ap) -- 2.20.1