From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 22 Apr 2016 18:37:46 +0200 Subject: [PATCH v2 10/11] arm: Add Aspeed machine In-Reply-To: References: <1461225849-28074-1-git-send-email-joel@jms.id.au> <20160422052005.GA4520@afzalpc> Message-ID: <4284450.j3L3LXq8Ay@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 22 April 2016 15:02:35 Joel Stanley wrote: > On Fri, Apr 22, 2016 at 2:50 PM, Afzal Mohammed wrote: > > On Fri, Apr 22, 2016 at 09:02:54AM +1000, Benjamin Herrenschmidt wrote: > >> On Fri, 2016-04-22 at 08:28 +1000, Benjamin Herrenschmidt wrote: > > > >> > It may or may not be already correct, you don't necessarily have a > >> > serial enabled bootloader or it might be using a UART driver that > >> > doesn't use the 'standard' divisors etc... This just sanitizes it. > > > >> On a second thought ... if we chose to not support random crap vendor > >> uboots, we could make it a requirement that this register is already > >> set appropriately by the bootloader to match what's in the device-tree > >> I suppose... > > > > ARM Linux expects bootloader to initialize one serial port > > (Documentation/arm/Booting). Though mentioned as optional, recommended > > so far haven't seen one w/o that. And to debug at early boot stage > > like in assembly and where uart driver is not yet up, this helps in > > being able to debug w/o jtag. > > I did some testing and on the palmetto we still get console with our > u-boot, so I'll drop the divisor change. > Ok, very good. We can always add it back if we see a good reason for needing it, but I think it's better to start by adding the drivers and leave workarounds like this for later when we know if we actually require them. Arnd