Re: [PATCH] make drivers/scsi/sym53c8xx.c check request_region's

[=?ISO-8859-1?Q?G=E9rard_Roudier?=]

On Thu, 25 Jan 2001, Rasmus Andersen wrote:

> Hi.
> 
> I apparently forgot to cc the lists on this one. Replies should be cc'ed
> to [e-mail] also.
> 
> Thanks.

The change should not harm, but request_region() is very unlikely to fail
here. Reason is that the drivers previously perform a check_region() in
order to synchronyze with any other driver that may have attached the same
device (candidates are : sym53c8xx, ncr53c8xx, 53c7,8xx)

By the way, as PCI only device drivers, the [sym|ncr]53c8xx drivers want
to use MMIO and not normal IO. The 'normal IO' path is here for archs that
donnot want to accept MMIO. Note that there are a couple of strangenesses
here:

1) The FreeBSD sym driver (derived from sym53c8xx) works with MMIO on
   FreeBSD/Alpha, but the sym53c8xx fails MMIO under Linux/Alpha.
2) Power/PC port wants drivers to use normal IOs even on machines that
   only have MMIO.

(2) looks rather a weirdness than a strangeness. :-)

Gérard.

> ----- Forwarded message from Rasmus Andersen <[e-mail]> -----
> 
> Date: Tue, 23 Jan 2001 23:37:14 +0100
> From: Rasmus Andersen <[e-mail]>
> To: [e-mail]
> Subject: [PATCH] make drivers/scsi/sym53c8xx.c check request_region's return code (241p9)
> User-Agent: Mutt/1.2.4i
> 
> Hi.
> 
> The following patch makes drivers/scsi/sym53c8xx.c check the return
> code of request_region. It applies cleanly against ac10 and 241p9.
> 
> Please comment.
> 
> 
> 
> --- linux-ac10-clean/drivers/scsi/sym53c8xx.c	Mon Jan  1 19:23:21 2001
> +++ linux-ac10/drivers/scsi/sym53c8xx.c	Sun Jan 21 21:40:54 2001
> @@ -5817,7 +5817,11 @@
>  	*/
>  
>  	if (device->slot.io_port) {
> -		request_region(device->slot.io_port, np->base_ws, NAME53C8XX);
> +		if (!request_region(device->slot.io_port, np->base_ws, 
> +				    NAME53C8XX)) {
> +			printk(KERN_ERR "Cannot mmap IO range.\n");
> +			goto attach_error;
> +		}
>  		np->base_io = device->slot.io_port;
>  	}
> 
> --- linux-ac10-clean/drivers/scsi/sym53c8xx_comm.h	Mon Oct 16 21:56:50 2000
> +++ linux-ac10/drivers/scsi/sym53c8xx_comm.h	Mon Jan 22 21:56:46 2001
> @@ -1799,7 +1799,8 @@
>  	**    Get access to chip IO registers
>  	*/
>  #ifdef NCR_IOMAPPED
> -	request_region(devp->slot.io_port, 128, NAME53C8XX);
> +	if (!request_region(devp->slot.io_port, 128, NAME53C8XX))
> +		return;
>  	devp->slot.base_io = devp->slot.io_port;
>  #else
>  	devp->slot.reg = (struct ncr_reg *) remap_pci_mem(devp->slot.base, 128);
> 
> 
> -- 
> Regards,
>         Rasmus([e-mail])
> 
> It isn't pollution that's harming the environment. It's the impurities in
> our air and water that are doing it.  -Former U.S. Vice-President Dan
> Quayle
> 
> ----- End forwarded message -----
> 
> -- 
> Regards,
>         Rasmus([e-mail])
> 
> Freedom of the press is limited to those who own one.
>                                  - A.J. Liebling 
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