From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Date: Thu, 06 Nov 2014 13:26:45 +0000 Subject: Re: [PATCH v3/resend] ARM: shmobile: Add early debugging support using SCIF(A) Message-Id: <20777697.th35W64j5e@wuerfel> List-Id: References: <1415273910-32356-1-git-send-email-geert+renesas@glider.be> <3499638.LG41cHl0JS@wuerfel> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Thursday 06 November 2014 13:33:58 Geert Uytterhoeven wrote: > > On Thu, Nov 6, 2014 at 12:53 PM, Arnd Bergmann wrote: > > On Thursday 06 November 2014 12:38:30 Geert Uytterhoeven wrote: > >> Add serial port debug macros for the SCIF(A) serial ports. > >> This includes all shmobile SoCs, except for EMEV2. > > > I don't object to this patch going in, but have you looked at doing > > just earlycon instead? We are still missing some fixmap changes > > I was thinking about earlycon support... > > > before that works on arm32, but in general, early looks nicer than > > Good to know there are still some parts missing. > > > debug_ll because it doesn't require you to build for a particular > > machine, with the downside that it's not available as early during > > boot. > > Hence we're gonna need debug_ll anyway? > So far I only needed it for real early issues. It depends on whether you were missing it in the past. shmobile so far only supports early_platform, which isn't quite as early as earlycon. If early_platform was good enough then earlycon will work too. > >> + { > >> + .virtual = 0xffe40000, > >> + .pfn = __phys_to_pfn(0xffe40000), > >> + .length = SZ_64K, > >> + .type = MT_DEVICE_NONSHARED > >> + }, > >> +#endif /* CONFIG_DEBUG_R8A7779_SCIF2 */ > >> }; > > > > This should be done automatically if you call debug_ll_io_init() or > > have an empty map_io() callback. > > On r8a7779 map_io() is not empty, but it didn't cover the SCIF registers, > cfr. the commit log: > > > > 4. On SoCs using the legacy machine_desc.map_io(), an identity mapping > > > of the SCIF(A) registers must be set up in .map_io(). On all but > > > r8a7779 this was already done. Ok. You can of course just call debug_ll_io_init() manually from the map_io function, it will create the same mapping. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Thu, 06 Nov 2014 14:26:45 +0100 Subject: [PATCH v3/resend] ARM: shmobile: Add early debugging support using SCIF(A) In-Reply-To: References: <1415273910-32356-1-git-send-email-geert+renesas@glider.be> <3499638.LG41cHl0JS@wuerfel> Message-ID: <20777697.th35W64j5e@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday 06 November 2014 13:33:58 Geert Uytterhoeven wrote: > > On Thu, Nov 6, 2014 at 12:53 PM, Arnd Bergmann wrote: > > On Thursday 06 November 2014 12:38:30 Geert Uytterhoeven wrote: > >> Add serial port debug macros for the SCIF(A) serial ports. > >> This includes all shmobile SoCs, except for EMEV2. > > > I don't object to this patch going in, but have you looked at doing > > just earlycon instead? We are still missing some fixmap changes > > I was thinking about earlycon support... > > > before that works on arm32, but in general, early looks nicer than > > Good to know there are still some parts missing. > > > debug_ll because it doesn't require you to build for a particular > > machine, with the downside that it's not available as early during > > boot. > > Hence we're gonna need debug_ll anyway? > So far I only needed it for real early issues. It depends on whether you were missing it in the past. shmobile so far only supports early_platform, which isn't quite as early as earlycon. If early_platform was good enough then earlycon will work too. > >> + { > >> + .virtual = 0xffe40000, > >> + .pfn = __phys_to_pfn(0xffe40000), > >> + .length = SZ_64K, > >> + .type = MT_DEVICE_NONSHARED > >> + }, > >> +#endif /* CONFIG_DEBUG_R8A7779_SCIF2 */ > >> }; > > > > This should be done automatically if you call debug_ll_io_init() or > > have an empty map_io() callback. > > On r8a7779 map_io() is not empty, but it didn't cover the SCIF registers, > cfr. the commit log: > > > > 4. On SoCs using the legacy machine_desc.map_io(), an identity mapping > > > of the SCIF(A) registers must be set up in .map_io(). On all but > > > r8a7779 this was already done. Ok. You can of course just call debug_ll_io_init() manually from the map_io function, it will create the same mapping. Arnd