linux-kernel - Re: [PATCH v3] Input: synaptics-rmi4 - stop scanning PDT after two empty pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20161108013401.GA10133@dtor-ws>
Date:   Mon, 7 Nov 2016 17:34:01 -0800
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Nick Dyer <nick@...anahar.org>
Cc:     Andrew Duggan <aduggan@...aptics.com>,
        Christopher Heiny <cheiny@...aptics.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Chris Healy <cphealy@...il.com>, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] Input: synaptics-rmi4 - stop scanning PDT after two
 empty pages

On Wed, Oct 26, 2016 at 09:57:34PM +0100, Nick Dyer wrote:
> We have encountered some RMI4 firmwares where there are blank pages in
> between PDT pages which contain functions. This change makes them
> correctly enumerate all functions on the device.
> 
> Tested on S7817 (has empty page 2).
> 
> Signed-off-by: Nick Dyer <nick@...anahar.org>
> [Tested successfully on S7817 and S7300 Synaptics touch controllers]
> Tested-by: Chris Healy <cphealy@...il.com>
> Reviewed-by: Andrew Duggan <aduggan@...aptics.com>

Applied, thank you.

> ---
>  drivers/input/rmi4/rmi_driver.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
> index 4a88312..425bd19 100644
> --- a/drivers/input/rmi4/rmi_driver.c
> +++ b/drivers/input/rmi4/rmi_driver.c
> @@ -422,6 +422,7 @@ static void rmi_driver_copy_pdt_to_fd(const struct pdt_entry *pdt,
>  
>  static int rmi_scan_pdt_page(struct rmi_device *rmi_dev,
>  			     int page,
> +			     int *empty_pages,
>  			     void *ctx,
>  			     int (*callback)(struct rmi_device *rmi_dev,
>  					     void *ctx,
> @@ -449,7 +450,16 @@ static int rmi_scan_pdt_page(struct rmi_device *rmi_dev,
>  			return retval;
>  	}
>  
> -	return (data->f01_bootloader_mode || addr == pdt_start) ?
> +	/*
> +	 * Count number of empty PDT pages. If a gap of two pages
> +	 * or more is found, stop scanning.
> +	 */
> +	if (addr == pdt_start)
> +		++*empty_pages;
> +	else
> +		*empty_pages = 0;
> +
> +	return (data->f01_bootloader_mode || *empty_pages >= 2) ?
>  					RMI_SCAN_DONE : RMI_SCAN_CONTINUE;
>  }
>  
> @@ -459,10 +469,12 @@ static int rmi_scan_pdt(struct rmi_device *rmi_dev, void *ctx,
>  					const struct pdt_entry *entry))
>  {
>  	int page;
> +	int empty_pages = 0;
>  	int retval = RMI_SCAN_DONE;
>  
>  	for (page = 0; page <= RMI4_MAX_PAGE; page++) {
> -		retval = rmi_scan_pdt_page(rmi_dev, page, ctx, callback);
> +		retval = rmi_scan_pdt_page(rmi_dev, page, &empty_pages,
> +					   ctx, callback);
>  		if (retval != RMI_SCAN_CONTINUE)
>  			break;
>  	}
> -- 
> 2.7.4
> 

-- 
Dmitry