Re: [PATCH] atmel_lcdfb: FIFO underflow management

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 16 May 2008 14:34:12 +0200
Nicolas Ferre <nicolas.ferre@atmel.com> wrote:

> Manage atmel_lcdfb FIFO underflow
> 
> Resetting the LCD and DMA allows to fix screen shifting after a 
> FIFO underflow. It follows reset sequence from errata 
> "LCD Screen Shifting After a Reset".
> 

This looks like 2.6.26-worthy bugfix to me?  But as commonly happens,
that isn't terribly clear.

> +	if (status & ATMEL_LCDC_UFLWI) {
> +		dev_warn(info->device, "FIFO underflow %#x\n", status);
> +		/* reset DMA and FIFO to avoid screen shifting */
> +		schedule_work(&sinfo->task);
> +	}
> +	lcdc_writel(sinfo, ATMEL_LCDC_ICR, status);
>  	return IRQ_HANDLED;
>  }

Shouldn't there be a cancel_work_sync() in atmel_lcdfb_exit()?


> +	/* Initialize bottom half workqueue */

Well.  "bottom half" is an ancient term for softirqs, not for the
new-fangled process-context callbacks.

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