On 08.08.2013 18:14, Petko Manolov wrote: > On Wed, 7 Aug 2013, Jussi Kivilinna wrote: > >> rtl8150 allocates URB transfer_buffer and setup_packet as part of same >> structure 'struct async_req'. This can cause same cacheline to be >> DMA-mapped twice with same URB. This can lead to memory corruption on >> some systems. > > I can see performance impact due to the double mapping. However, memory > corruption seems a bit too much for sane cache and DMA controllers. Out > of interest - which is the architecture that will potentially corrupt the > memory. rtlwifi driver had similar structure to allocate both setup_packet and transfer_buffer in single go (overlapping dma-mapping cachelines) and this caused problems on ARM/sunxi. Problems means: memory corruptions at random locations, device freezes and lock-ups. -Jussi > > > cheers, > Petko > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
