[PATCH 07/13] uimage: improve transfer speed

vj vicencb at gmail.com
Mon Oct 8 16:48:01 EDT 2012


On Mon, Oct 8, 2012 at 10:01 PM, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> On Mon, Oct 08, 2012 at 12:01:21AM +0200, Vicente wrote:
>>
>> Signed-off-by: Vicente <vicencb at gmail.com>
>
> Do you have some numbers which cases this speeds up and how much?
>
> Sascha
>
>> ---
>>  common/uimage.c | 26 ++++++++++++++++++++++++--
>>  1 file changed, 24 insertions(+), 2 deletions(-)
>>
>> diff --git a/common/uimage.c b/common/uimage.c
>> index c72db41..18c5b01 100644
>> --- a/common/uimage.c
>> +++ b/common/uimage.c
>> @@ -28,6 +28,8 @@
>>  #include <rtc.h>
>>  #include <filetype.h>
>>  #include <memory.h>
>> +#include <linux/stat.h>
>> +#include <sizes.h>
>>
>>  #ifdef CONFIG_UIMAGE_MULTI
>>  static inline int uimage_is_multi_image(struct uimage_handle *handle)
>> @@ -380,15 +382,35 @@ struct resource *file_to_sdram(const char *filename, unsigned long adr)
>>       struct resource *res;
>>       size_t size = BUFSIZ;
>>       size_t ofs = 0;
>> +     size_t now;
>>       int fd;
>> +     struct stat s;
>>
>>       fd = open(filename, O_RDONLY);
>>       if (fd < 0)
>>               return NULL;
>>
>> -     while (1) {
>> -             size_t now;
>> +     /* TODO: use fstat(fd, &s) when implemented and avoid reopening file */
>> +     if (stat(filename, &s) == 0 && s.st_size <= SZ_1G) {
>> +             /*
>> +              * As the file size is known we can read it at once and improve
>> +              * transfer speed.
>> +              */
>> +             res = request_sdram_region("image", adr, s.st_size);
>> +             if (!res) {
>> +                     printf("unable to request SDRAM 0x%08lx-0x%08lx\n",
>> +                             adr, adr + s.st_size - 1);
>> +                     goto out;
>> +             }
>>
>> +             now = read_full(fd, (void *)(res->start), s.st_size);
>> +             if (now < s.st_size) {
>> +                     release_sdram_region(res);
>> +                     res = NULL;
>> +             }
>> +             goto out;
>> +     }
>> +     while (1) {
>>               res = request_sdram_region("image", adr, size);
>>               if (!res) {
>>                       printf("unable to request SDRAM 0x%08lx-0x%08lx\n",
>> --
>> 1.7.12.2
>>
>>
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>>
>
> --
> Pengutronix e.K.                           |                             |
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Yes,
 for example when transferring a 51MB initramfs from PC to tablet
through omap4_usbboot_fs it goes from 6MBps to 15MBps, from 8 seconds
to 3.3.

Regards,
  Vicente.



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