| Message ID | 1396007435-20100-1-git-send-email-wsa@the-dreams.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Wolfram, Neil, On Fri, 28 Mar 2014, Wolfram Sang wrote: > From: NeilBrown <neilb@suse.de> > > If omap_device_alloc is given 2 or more "struct omap_hwmod" it will try > to register the 'main_clk' of each of them with the same alias - "fck" - > against the same device. This fails. So to avoid a warning, don't even > try. > > Signed-off-by: NeilBrown <neilb@suse.de> > [wsa: ported to top-of-tree] > Signed-off-by: Wolfram Sang <wsa@sang-engineering.com> What devices and hwmods cause this warning on AM335x? Ideally, there should only be one hwmod per device. Usually when multiple hwmods are stacked up for a device, it means that something isn't right - either the hwmod data, or the device driver itself. In the specific context of this patch, the problem would be: what if the two hwmods have different main_clk entries? Which one should be associated with the "fck" alias? - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Paul, thanks for the reply! > > If omap_device_alloc is given 2 or more "struct omap_hwmod" it will try > > to register the 'main_clk' of each of them with the same alias - "fck" - > > against the same device. This fails. So to avoid a warning, don't even > > try. > > > > Signed-off-by: NeilBrown <neilb@suse.de> > > [wsa: ported to top-of-tree] > > Signed-off-by: Wolfram Sang <wsa@sang-engineering.com> > > What devices and hwmods cause this warning on AM335x? Ideally, there > should only be one hwmod per device. Usually when multiple hwmods are > stacked up for a device, it means that something isn't right - either the > hwmod data, or the device driver itself. I applied the patch because of the edma driver DT entry for the am335x. Check am33xx.dtsi, it has multiple hwmods. I also get this message printed for the d_can driver with am335x; they have two entries in drivers/clk/ti/clk-33xx.c. Probably as a workaround to match the desired clock name for the d_can driver? Didn't really investigate yet. > In the specific context of this patch, the problem would be: what if the > two hwmods have different main_clk entries? Which one should be > associated with the "fck" alias? Sadly, I am in a board bringup phase and can't really contribute to the discussions. Lots of other issues to tackle at the moment. All the best, Wolfram
(+ Matt Porter, Joel Fernandes) Hi Wolfram, On Thu, 17 Apr 2014, Wolfram Sang wrote: > thanks for the reply! Always good to hear from you - > > > If omap_device_alloc is given 2 or more "struct omap_hwmod" it will try > > > to register the 'main_clk' of each of them with the same alias - "fck" - > > > against the same device. This fails. So to avoid a warning, don't even > > > try. > > > > > > Signed-off-by: NeilBrown <neilb@suse.de> > > > [wsa: ported to top-of-tree] > > > Signed-off-by: Wolfram Sang <wsa@sang-engineering.com> > > > > What devices and hwmods cause this warning on AM335x? Ideally, there > > should only be one hwmod per device. Usually when multiple hwmods are > > stacked up for a device, it means that something isn't right - either the > > hwmod data, or the device driver itself. > > I applied the patch because of the edma driver DT entry for the am335x. > Check am33xx.dtsi, it has multiple hwmods. I just took a look at the EDMA DT data vis-a-vis SPRUH73J Section 11.2.2 "Third-Party Transfer Controller (TPTC) Integration". This section clearly indicates that the TPTCs have their own L3 Fast Interconnect slave ports, marked as "CFG Slave". Cross-checking this with Table 2-1 "L3 Memory Map" indeed indicates that these three devices have their own 1MB physical address ranges hanging off the L3. So the EDMA DT data is flat-out wrong here and should not have been merged. Looks like it was added by commit 505975d3802f8d3a3c0905f38056213d06997b36 ("ARM: dts: AM33XX: Add EDMA support"). Matt, Joel, could you please fix this data? The TPTCs are separate IP blocks with separate address ranges and MPU IRQs and should have separate DT nodes. > I also get this message printed for the d_can driver with am335x; they > have two entries in drivers/clk/ti/clk-33xx.c. Probably as a workaround > to match the desired clock name for the d_can driver? Didn't really > investigate yet. That's pretty weird. I wonder where the second fck alias is coming from? The DT & hwmod data for those devices looks relatively straightforward. Is the hwmod code adding fck aliases for both of the entries from the clock file? > > In the specific context of this patch, the problem would be: what if the > > two hwmods have different main_clk entries? Which one should be > > associated with the "fck" alias? > > Sadly, I am in a board bringup phase and can't really contribute to the > discussions. Lots of other issues to tackle at the moment. Understood. Good luck with your board - - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> > I also get this message printed for the d_can driver with am335x; they > > have two entries in drivers/clk/ti/clk-33xx.c. Probably as a workaround > > to match the desired clock name for the d_can driver? Didn't really > > investigate yet. > > That's pretty weird. I wonder where the second fck alias is coming from? > The DT & hwmod data for those devices looks relatively straightforward. > Is the hwmod code adding fck aliases for both of the entries from the > clock file? $ grep 'can' drivers/clk/ti/clk-33xx.c * This program is free software; you can redistribute it and/or DT_CLK(NULL, "dcan0_fck", "dcan0_fck"), DT_CLK("481cc000.d_can", NULL, "dcan0_fck"), DT_CLK(NULL, "dcan1_fck", "dcan1_fck"), DT_CLK("481d0000.d_can", NULL, "dcan1_fck"), I quickly tried to remove the entries not specifying platform devices but that prevented my system from booting (Huh?). Still, no time to really check it, though. Thanks, Wolfram
diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c index 01ef59def44b..ce132d0084d2 100644 --- a/arch/arm/mach-omap2/omap_device.c +++ b/arch/arm/mach-omap2/omap_device.c @@ -84,6 +84,7 @@ static void _add_clkdev(struct omap_device *od, const char *clk_alias, * and main clock * @od: struct omap_device *od * @oh: struct omap_hwmod *oh + * @sub: if > 0, this is a subordinate device, so don't try to register fck * * For the main clock and every optional clock present per hwmod per * omap_device, this function adds an entry in the clkdev table of the @@ -99,11 +100,12 @@ static void _add_clkdev(struct omap_device *od, const char *clk_alias, * No return value. */ static void _add_hwmod_clocks_clkdev(struct omap_device *od, - struct omap_hwmod *oh) + struct omap_hwmod *oh, int sub) { int i; - _add_clkdev(od, "fck", oh->main_clk); + if (!sub) + _add_clkdev(od, "fck", oh->main_clk); for (i = 0; i < oh->opt_clks_cnt; i++) _add_clkdev(od, oh->opt_clks[i].role, oh->opt_clks[i].clk); @@ -468,7 +470,7 @@ have_everything: for (i = 0; i < oh_cnt; i++) { hwmods[i]->od = od; - _add_hwmod_clocks_clkdev(od, hwmods[i]); + _add_hwmod_clocks_clkdev(od, hwmods[i], i); } return od;