Re: [PATCH] libata: blacklist for early irq problem

[Mark Lord <liml@rtr.ca>]

Albert Lee wrote:
>...
>  
> +	/* some drives raise INTRQ early before clearing BSY */
> +	if (unlikely(qc->dev->horkage & ATA_HORKAGE_EARLY_IRQ))
> +		/* wait up to 10 microseconds for BSY to clear */
> +		ata_busy_wait_alt(ap, ATA_BUSY, ATA_EARLY_IRQ_WAIT);
> +
>  	/* check altstatus */
>  	status = ata_altstatus(ap);
>  	if (status & ATA_BUSY)
...

I dunno.

I think a much simpler patch could address the same situation,
with *no blacklist* to maintain, and no added overhead required:

	/* check altstatus */
+	retries = 10;
+	while (((status = ata_altstatus(ap)) & ATA_BUSY) && --retries) {
+		udelay(1);
+	}
-	status = ata_altstatus(ap);
	if (status & ATA_BUSY)

This still just does a single access in the hot path, but without any
real added complexity otherwise.

????