Messages in this thread | | | Date | Wed, 12 Oct 2011 14:46:49 +0200 | Subject | Re: [Patch] Increase USBFS Bulk Transfer size | From | Markus Rechberger <> |
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On Wed, Oct 12, 2011 at 2:36 PM, Markus Rechberger <mrechberger@gmail.com> wrote: > We have 2 products which can perform better with increased Bulk transfers > > Device No. 1: > According to the hardware spec of on of our product > Available Bulk Transfer Size are: > - 188 * n bytes, where n = 1 ~ 256. > > Although we can drive that one with 15K as well when setting the HW > register down to it. > > Device No. 2 > only creates jitter video with Bulk transfer sizes which are below > 24064 bytes, no such chipfeature is available > to decrease the bulk transfer size. > http://sundtek.de/images/dtvjitter2.jpg > with transfer size of 24064: > http://sundtek.de/images/gooddata.jpg > > The patch takes the features of Device No. 1 into account allowing a > maximum buffer of 48128 bytes. > > Those issues have been evaluated with MacOSX and a customized patched > Linux version. > Device No. 2 also corrupts on MacOSX with too small packet sizes, > Windows and Mac are using 24064 bytes. > > Default Bulk Transfersize of device No. 1 is around 1-2k which leads > to very high cpu usage, updating it to 15k lowers that one. >
Signed-off-by: Markus Rechberger <mrechberger@gmail.com>
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