16a2e7d359
Pl080 Manual says: "Bursts do not cross the 1KB address boundary" We can program the controller to cross 1 KB boundary on a burst and controller can take care of this boundary condition by itself. Following is the discussion with ARM Technical Support Guys (David): [Viresh] Manual says: "Bursts do not cross the 1KB address boundary" What does that actually mean? As, Maximum size transferable with a single LLI is 4095 * 4 =16380 ~ 16KB. So, if we don't have src/dest address aligned to burst size, we can't use this big of an LLI. [David] There is a difference between bursts describing the total data transferred by the DMA controller and AHB bursts. Bursts described by the programmable parameters in the PL080 have no direct connection with the bursts that are seen on the AHB bus. The statement that "Bursts do not cross the 1KB address boundary" in the TRM is referring to AHB bursts, where this limitation is a requirement of the AHB spec. You can still issue bursts within the PL080 that are in excess of 1KB. The PL080 will make sure that its bursts are broken down into legal AHB bursts which will be formatted to ensure that no AHB burst crosses a 1KB boundary. Based on above discussion, this patch removes all code related to 1 KB boundary as we are not required to handle this in driver. Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com> |
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| Kbuild | ||