[U-Boot] [PATCH v4] usb: align buffers at cacheline

[puneets]

On Friday 02 March 2012 07:16 PM, Marek Vasut wrote:
>> As DMA expects the buffers to be equal and larger then
>> cache lines, This aligns buffers at cacheline.
>>
>> Signed-off-by: Puneet Saxena<puneets at nvidia.com>
>> ---
>>
>> Changes for V3:
>>      - Removed local descriptor elements copy to global descriptor elements
>>      - Removed "Signed-off-by: Jim Lin<jilin at nvidia.com>" from commit
>> message
>>
>> Changes for V4:
>>      - Added memcpy to copy local descriptor to global descriptor.
>>        Without that, USB version, class, vendor, product Id...etc is not
>> configured. This information is useful for loading correct device driver
>> and possible configuration.
>>
>>
>>   common/cmd_usb.c            |    3 +-
>>   common/usb.c                |   56
>> ++++++++++++++++++++++------------------ common/usb_storage.c        |
>> 59 ++++++++++++++++++++---------------------- disk/part_dos.c
>> |    2 +-
>>   drivers/usb/host/ehci-hcd.c |    8 ++++++
>>   include/scsi.h              |    4 ++-
>>   6 files changed, 73 insertions(+), 59 deletions(-)
>>
>> diff --git a/common/cmd_usb.c b/common/cmd_usb.c
>> index 320667f..bca9d94 100644
>> --- a/common/cmd_usb.c
>> +++ b/common/cmd_usb.c
>> @@ -150,7 +150,8 @@ void usb_display_class_sub(unsigned char dclass,
>> unsigned char subclass,
>>
>>   void usb_display_string(struct usb_device *dev, int index)
>>   {
>> -	char buffer[256];
>> +	ALLOC_CACHE_ALIGN_BUFFER(char, buffer, 256);
>> +
>>   	if (index != 0) {
>>   		if (usb_string(dev, index,&buffer[0], 256)>  0)
>>   			printf("String: \"%s\"", buffer);
>> diff --git a/common/usb.c b/common/usb.c
>> index 6e21ae2..42a44e2 100644
>> --- a/common/usb.c
>> +++ b/common/usb.c
>> @@ -73,7 +73,6 @@ static struct usb_device usb_dev[USB_MAX_DEVICE];
>>   static int dev_index;
>>   static int running;
>>   static int asynch_allowed;
>> -static struct devrequest setup_packet;
>>
>>   char usb_started; /* flag for the started/stopped USB status */
>>
>> @@ -185,23 +184,25 @@ int usb_control_msg(struct usb_device *dev, unsigned
>> int pipe, unsigned short value, unsigned short index,
>>   			void *data, unsigned short size, int timeout)
>>   {
>> +	ALLOC_CACHE_ALIGN_BUFFER(struct devrequest, setup_packet,
>> +		sizeof(struct devrequest));
>>   	if ((timeout == 0)&&  (!asynch_allowed)) {
>>   		/* request for a asynch control pipe is not allowed */
>>   		return -1;
>>   	}
>>
>>   	/* set setup command */
>> -	setup_packet.requesttype = requesttype;
>> -	setup_packet.request = request;
>> -	setup_packet.value = cpu_to_le16(value);
>> -	setup_packet.index = cpu_to_le16(index);
>> -	setup_packet.length = cpu_to_le16(size);
>> +	setup_packet->requesttype = requesttype;
>> +	setup_packet->request = request;
>> +	setup_packet->value = cpu_to_le16(value);
>> +	setup_packet->index = cpu_to_le16(index);
>> +	setup_packet->length = cpu_to_le16(size);
>>   	USB_PRINTF("usb_control_msg: request: 0x%X, requesttype: 0x%X, " \
>>   		   "value 0x%X index 0x%X length 0x%X\n",
>>   		   request, requesttype, value, index, size);
>>   	dev->status = USB_ST_NOT_PROC; /*not yet processed */
>>
>> -	submit_control_msg(dev, pipe, data, size,&setup_packet);
>> +	submit_control_msg(dev, pipe, data, size, setup_packet);
>>   	if (timeout == 0)
>>   		return (int)size;
>>
>> @@ -698,7 +699,7 @@ static int usb_string_sub(struct usb_device *dev,
>> unsigned int langid, */
>>   int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
>>   {
>> -	unsigned char mybuf[USB_BUFSIZ];
>> +	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, mybuf, USB_BUFSIZ);
>>   	unsigned char *tbuf;
>>   	int err;
>>   	unsigned int u, idx;
>> @@ -798,7 +799,7 @@ int usb_new_device(struct usb_device *dev)
>>   {
>>   	int addr, err;
>>   	int tmp;
>> -	unsigned char tmpbuf[USB_BUFSIZ];
>> +	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ);
>>
>>   	/* We still haven't set the Address yet */
>>   	addr = dev->devnum;
>> @@ -909,7 +910,7 @@ int usb_new_device(struct usb_device *dev)
>>   	tmp = sizeof(dev->descriptor);
>>
>>   	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
>> -				&dev->descriptor, sizeof(dev->descriptor));
>> +				 desc, sizeof(dev->descriptor));
>>   	if (err<  tmp) {
>>   		if (err<  0)
>>   			printf("unable to get device descriptor (error=%d)\n",
>> @@ -919,14 +920,18 @@ int usb_new_device(struct usb_device *dev)
>>   				"(expected %i, got %i)\n", tmp, err);
>>   		return 1;
>>   	}
>> +
>> +	/* Now copy the local device descriptor to global device descriptor*/
>> +	memcpy(&dev->descriptor, desc, sizeof(dev->descriptor));
> Hey, it's almost perfect!
>
> Just one last question -- why do you need to copy this stuff?
We need to copy this stuff as I spoke in previous reply  -
"memcpy" is needed to configure Usb version, vendor id, prod Id ..etc
>  of the device. Its also useful to hook actual device driver and detect
>  no. of configuration supported. The effect can be verified 
with/without using memcpy
in "usb tree" and "usb info" commands.


> It's because dev-
>> descriptor is unaligned?
No, As global dev - descriptor is unaligned we are passing aligned local 
dev-desc and memcpy in global.
> M

Thanx,
Puneet

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