On Tuesday, September 01, 2015 at 02:32:26 PM, Jian Luo wrote: > Hi Marek,
Hi! > On 01.09.2015 14:03, Marek Vasut wrote: > > On Tuesday, September 01, 2015 at 01:49:43 PM, Jian Luo wrote: > ----snip---- > > >> What about calling socfpga_sdram_apply_static_cfg() direct in > >> socfpga_load() in drivers/fpga/socfpga.c to make it generic? > > > > Which code exactly do you refer to ? > > I mean something like this. > > diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c > index 4448250..d0f67f6 100644 > --- a/drivers/fpga/socfpga.c > +++ b/drivers/fpga/socfpga.c > @@ -300,5 +300,12 @@ int socfpga_load(Altera_desc *desc, const void > *rbf_data, size_t rbf_size) > return status; > > /* Ensure the FPGA entering user mode */ > - return fpgamgr_program_poll_usermode(); > + status = fpgamgr_program_poll_usermode(); > + if (status) > + return status; > + > + /* Latch FPGA2SDRAM bridge configuration */ > + socfpga_sdram_apply_static_cfg(); > + > + return 0; > } > > >> socfpga_load() already did step 1 and 2. > >> Is there any side effect when fpga2sdram bridge is not used? > > > > The idea is to keep the FPGA programming code and the code which > > controls the bridges separate. The reason for that is that you can have > > content in the FPGA which is running completely independent of the HPS > > software. You don't always need to enable the bridges. > > No, it's the other way around here. > socfpga_load() runs eventually when command "fpga load" is called. > So when I explicitly use "fpga load" command, the old FPGA program is > expected to stop running, right? Right > And I don't want to enable the bridge here, just to latch the SDRAM > configuration. So what you want to do is "bridge disable ; fpga load ... ; bridge enable", isn't that the correct sequence ? I might be missing something though, sorry. > > The FPGA2SDRAM bridge (or, more like fpga2hps bridge) is used for stuff > > like framebuffers implemented in the FPGA, so that the FPGA can fetch > > data from the SDRAM. > > > > Best regards, > > Marek Vasut > > Best regards, > > Jian Luo Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot