Messages in this thread | | | Subject | Re: [PATCH v5 3/6] ACPI: parse SPCR and enable matching console | From | Aleksey Makarov <> | Date | Tue, 22 Mar 2016 20:04:11 +0300 |
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On 03/22/2016 07:07 PM, Peter Hurley wrote: > On 03/22/2016 04:09 AM, Andy Shevchenko wrote: >> On Tue, Mar 22, 2016 at 12:46 PM, Aleksey Makarov >> <aleksey.makarov@linaro.org> wrote:
>>> + sprintf(opts, "%s,%s,0x%llx,%d", uart, iotype, >>> + table->serial_port.address, baud_rate); >> >> You may use snprintf(), though my question here what would happen on >> 32-bit kernel when you supply 64-bit address as an option? > > Yeah this should probably use %pa for the printf specifier. > > But note this exposes underlying bug in the earlycon support, because > that was originally written without 32/64-mixed bitness in mind; ie., > the address is parsed and handled as unsigned long in most places.
I don't quite follow this. table->serial_port.address is explicitly u64, not pointer, so, according to printk-formats.txt %llx is ok here, %pa is wrong. Am I missing something?
>>> /* >>> - * Just 'earlycon' is a valid param for devicetree earlycons; >>> - * don't generate a warning from parse_early_params() in that case >>> + * Just 'earlycon' is a valid param for devicetree and ACPI SPCR >>> + * earlycons; don't generate a warning from parse_early_params() >>> + * in that case >>> */ >>> - if (!buf || !buf[0]) >>> - return early_init_dt_scan_chosen_serial(); >>> + if (!buf || !buf[0]) { >>> + init_spcr_earlycon(); >> >>> + early_init_dt_scan_chosen_serial(); >>> + return 0; >> >> And you hide an error? > > Well, this is a little bit tricky because "earlycon" early parameter with > missing /chosen/stdout-path node is no longer an error, since ACPI may be > specifying the earlycon instead.
Agree, but note the email by Rob Herring. The code should be like this:
if (!buf || !buf[0]) { if (acpi_disabled) { return early_init_dt_scan_chosen_serial(); } else { init_spcr_earlycon(); return 0; } }
But that requires to have made ACPI/DT decision at this point.
Thank you Aleksey
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