1. 25 4月, 2008 36 次提交
  2. 20 3月, 2008 2 次提交
  3. 18 2月, 2008 2 次提交
    • M
      V4L/DVB (7180): em28xx: add URB_NO_TRANSFER_DMA_MAP, since urb->transfer_dma is set · 61b080d2
      Mauro Carvalho Chehab 提交于
      Thanks to Alan Stern <stern@rowland.harvard.edu> for pointing this issue.
      Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>
      61b080d2
    • M
      V4L/DVB (7179): Allow more than one em28xx board · 3687e1e6
      Mauro Carvalho Chehab 提交于
      em28xx driver is capable of handling more than one usb device. However, isoc
      transfers require a large amount of data to be transfered.
      
      Before this patch, just one em28xx board were enough to allocate more than 50%
      URBs:
      
      T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480 MxCh= 8
      B:  Alloc=480/800 us (60%), #Int=  0, #Iso=  2
      D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
      
      So, only one board could use an USB host at the same time. After the patch, it
      is possible to use more than one em28xx at the same time, on the same usb host,
      if the image size is slower or equal to 345600, since those images will
      require about 30% of the URBs:
      
      T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480 MxCh= 8
      B:  Alloc=232/800 us (29%), #Int=  0, #Iso=  2
      D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
      
      So, in thesis, after the patch, it would be possible to use up to 3 boards by
      each usb host, if the devices are generating small images.
      Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>
      3687e1e6