Re: [PATCH] Correct order for device unregistration in aic7xxx

[Christoph Hellwig <hch@infradead.org>]

On Tue, May 24, 2005 at 12:24:55PM +0200, Hannes Reinecke wrote:
> --- linux-2.6.12-rc4/drivers/scsi/aic7xxx/aic7xxx_osm.c.orig	2005-05-24 11:53:51.000000000 +0200
> +++ linux-2.6.12-rc4/drivers/scsi/aic7xxx/aic7xxx_osm.c	2005-05-24 11:55:30.000000000 +0200
> @@ -1748,12 +1748,6 @@ ahc_platform_free(struct ahc_softc *ahc)
>  	if (ahc->platform_data != NULL) {
>  		del_timer_sync(&ahc->platform_data->completeq_timer);
>  		tasklet_kill(&ahc->platform_data->runq_tasklet);
> -		if (ahc->platform_data->host != NULL) {
> -#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0)
> -			scsi_remove_host(ahc->platform_data->host);
> -#endif
> -			scsi_host_put(ahc->platform_data->host);
> -		}
>  
>  		/* destroy all of the device and target objects */
>  		for (i = 0; i < AHC_NUM_TARGETS; i++) {
> @@ -3623,6 +3617,20 @@ ahc_linux_init(void)
>  static void
>  ahc_linux_exit(void)
>  {
> +	struct ahd_softc *ahc;
> +
> +	/*
> +	 * Tear down midlayer first
> +	 */
> +	TAILQ_FOREACH(ahc, &ahd_tailq, links) {
> +		if (ahc->platform_data->host != NULL) {
> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0)
> +			scsi_remove_host(ahc->platform_data->host);
> +#endif
> +			scsi_host_put(ahc->platform_data->host);
> +		}
> +	}
> +

Sorrym this is not acceptable at all.  Please leave the host unregistration
in ->remove (and while we're at it the scsi_host_put happens far too early
in there) and move tearing down the DV thread later in ->remove.

You're current patch completely breaks hot removal.  Also please look
at aic7xxx in current Linus' tree - it's using the SPI transport class
and doesn't have it's own dv mechanisms anymore, only aic79xx needs
fixes or preferably someone porting over the recent aic7xxx changes.