Re: sata_mv query
From: Mark Lord <hidden>
Date: 2012-08-07 18:20:49
On 12-08-07 02:17 PM, Mark Lord wrote: ..
Say, here's a thought: We could get rid of (or relocate to upper layers) the busy-wait by having something similar get called from ata_qc_defer(). If you are feeling adventurous, here is a 100% untested patch to do just that. It looks correct to me, it compiles, but that's all I can say.
Whoops.. return codes were reversed. Here's the corrected patch. The attached copy is the better one to use -- my mailer mangles inline patches.
--- linux-3.4.4/drivers/ata/sata_mv.c 2012-06-22 14:37:50.000000000 -0400
+++ linux/drivers/ata/sata_mv.c 2012-08-07 14:14:43.554503157 -0400@@ -1388,6 +1388,17 @@ } } +static int mv_check_for_edma_empty_idle(struct ata_port *ap) +{ + void __iomem *port_mmio = mv_ap_base(ap); + const u32 empty_idle = (EDMA_STATUS_CACHE_EMPTY | EDMA_STATUS_IDLE); + + u32 edma_stat = readl(port_mmio + EDMA_STATUS); + if ((edma_stat & empty_idle) == empty_idle) + return 0; + return ATA_DEFER_PORT; +} + static int mv_qc_defer(struct ata_queued_cmd *qc) { struct ata_link *link = qc->dev->link;
@@ -1423,7 +1434,7 @@ * If the port is completely idle, then allow the new qc. */ if (ap->nr_active_links == 0) - return 0; + return mv_check_for_edma_empty_idle(ap); /* * The port is operating in host queuing mode (EDMA) with NCQ
Attachments
- xx_sata_mv_move_busywait.patch [text/x-patch] 838 bytes · preview