On Mon, 2011-02-07 at 08:08 +0200, ext Juuso Oikarinen wrote: > On Fri, 2011-02-04 at 13:35 +0200, ext juuso.oikarinen@xxxxxxxxx wrote: > > From: Juuso Oikarinen <juuso.oikarinen@xxxxxxxxx> > > > > Currently, the SDIO bus is claimed separately for each and every SDIO > > transaction - i.e. every register write/read etc. > > > > The SDIO claiming is a relatively heavy operation. In a worst case scenario, > > it will put the SDIO bus on suspend, stop relevant clocks etc which all can be > > extremely costly if done between each SDIO transaction. This has a dramatic > > impact on the maximum throughput achieved. > > > > The driver already manages its access to the bus as it needs to manage > > chipset ELP. This mechanism disables ELP for the duration of the whole bus > > access, consisting of multiple transactions. > > > > Into the IO layer, this patch implements a claim/unclaim function, which is > > used to claim access to the bus. Relevant functions are checked and updated to > > maintain correctly the claim reference counter, so that each claim is paired > > with a corresponding unclaim. > > > > For PLT and ad-hoc modes the bus is kept claimed contantly. > > > > For AP mode, this patch brings no change to the previous way of working, > > someone familiar with it and with the ability to test it may implement > > something similar as is done here for the other modes. > > > > For the SPI bus, the claim/unclaim functions are not implemented, i.e. no > > change to functionality. > > > > Signed-off-by: Juuso Oikarinen <juuso.oikarinen@xxxxxxxxx> > > --- > > I realised there are two separate issues here in one patch. I'll need to > split this into two patches. Also, there are some other issues I need to > address. > I'm dropping this patch. In the end our measurements didn't indicate any drastic benefits of this change, so its not worth contemplating more about it. -Juuso -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
