lkml.org 
[lkml]   [2015]   [Apr]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] firewire: firewire is a big-endian bus
Le 21/04/2015 15:13, Stefan Richter a écrit :
> On Apr 21 Laurent Vivier wrote:
>> So, dump config_rom data as big-endian values.
>>
>> The value given by /sys/bus/firewire/devices/fw0 were correctly
>> given on a big-endian host (like powermac) not on a little-endian host
>> (like PC), for instance:
>>
>> 00000000 87 a4 04 04 34 39 33 31 22 a2 00 f0 33 22 11 00 |....4931"...3"..|
>> 00000010 66 66 66 33 0b dd 05 00 c0 83 00 0c 1e 0d d0 03 |fff3............|
>> 00000020 03 00 00 81 01 00 00 17 08 00 00 81 b7 4c 06 00 |.............L..|
>> 00000030 00 00 00 00 00 00 00 00 75 6e 69 4c 69 46 20 78 |........uniLiF x|
>> 00000040 69 77 65 72 00 00 65 72 1c ff 03 00 00 00 00 00 |iwer..er........|
>> 00000050 00 00 00 00 75 6a 75 4a |....ujuJ|
>> 00000058
>>
>> instead of:
>>
>> 00000000 04 04 a4 87 31 33 39 34 f0 00 a2 22 00 11 22 33 |....1394...".."3|
>> 00000010 33 66 66 66 00 05 dd 0b 0c 00 83 c0 03 d0 0d 1e |3fff............|
>> 00000020 81 00 00 03 17 00 00 01 81 00 00 08 00 06 4c b7 |..............L.|
>> 00000030 00 00 00 00 00 00 00 00 4c 69 6e 75 78 20 46 69 |........Linux Fi|
>> 00000040 72 65 77 69 72 65 00 00 00 03 ff 1c 00 00 00 00 |rewire..........|
>> 00000050 00 00 00 00 4a 75 6a 75 |....Juju|
>> 00000058
>>
>> This patch corrects this.
>>
>> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> As defined in Documentation/ABI/stable/sysfs-bus-firewire we deliberately
> export the Configuration ROM as an array of host-endian quadlets. As a
> stable kernel ABI, this will not be changed.
OK, I understand.
>
> (A python script called crpp which transforms this kind of binary data into
> a richly annotated hexdump is available as part of the jujuutils package,
> or standalone from http://me.in-berlin.de/~s5r6/linux1394/utils/.)
Thank you for the information.

Regards,
Laurent
>
>> ---
>> drivers/firewire/core-device.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
>> index f9e3aee..5245567 100644
>> --- a/drivers/firewire/core-device.c
>> +++ b/drivers/firewire/core-device.c
>> @@ -399,14 +399,14 @@ static ssize_t config_rom_show(struct device *dev,
>> struct device_attribute *attr, char *buf)
>> {
>> struct fw_device *device = fw_device(dev);
>> - size_t length;
>> + size_t i;
>>
>> down_read(&fw_device_rwsem);
>> - length = device->config_rom_length * 4;
>> - memcpy(buf, device->config_rom, length);
>> + for (i = 0; i < device->config_rom_length; i++)
>> + ((u32 *)buf)[i] = be32_to_cpu(device->config_rom[i]);
>> up_read(&fw_device_rwsem);
>>
>> - return length;
>> + return i * 4;
>> }
>>
>> static ssize_t guid_show(struct device *dev,
>
>


[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2015-04-21 18:41    [W:0.056 / U:4.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site