| Message ID | 1459952294.10130.32.camel@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Wed, 2016-04-06 at 09:27 -0700, Peter Hurley wrote: > On 04/06/2016 07:18 AM, Mark Salter wrote: > > > > On Wed, 2016-04-06 at 11:52 +0100, Graeme Gregory wrote: > > > > > > On Wed, Apr 06, 2016 at 01:24:12PM +0300, Aleksey Makarov wrote: > > > > > > > > > > > > > > > > > > > > On 04/05/2016 07:27 PM, Mark Salter wrote: > > > > > > > > > > > > > > > Could you CC me on future postings of this series, please? > > > > > > > > > > So v3 fixed a problem where platforms using 8250 didn't work. > > > > > Then in v5, that fix was lost so 8250 no longer works. > > > > That fix was dropped because now this is implemented differently. > > > > Now the code uses the existing match() member of struct console. > > > > It has already been implemented for 8250. > > > > Probably SPCR table specifies incorrect data. > > > > It was reported that D02 board has similar issue. > > > > > > > The D02 issue referred to is the 8250 implementation they used has 32bit > > > only MMIO access which there is no manner to represent in SPCR. It also > > > doesn't use the "standard" 16550 clock rate so supplying a baud rate > > > makes it change to a random baud rate. > > So, the problem with Mustang and m400 was the mmio vs mmio32. > Bummer. Maybe that firmware can use a different DBG2 port designation to > indicate it's a DesignWare 8250 (or generically 32-bit mmio). > > > > > Right now, > > the kernel only supports mmio32 in the 8250_dw.c driver when probed with > > ACPI. > While that's true specifically for DesignWare 8250 + ACPI, that's not > true for _all_ 8250 + ACPI. > > > > > Other x86 machines just use legacy 8250 ports which don't need > > entries in the DSDT and use legacy io. > I find that statement hard to believe. I know for a fact ia64 servers didn't, > so the assertion that SPCR + 16550 + MMIO automatically means 32-bit data width > seems unlikely. You're right. Other than DesignWare, 8250 ports can be descibed with PNP IDs which is the bit I was missing. And all of those assume 8-bit width. So it seems a DBG2 port designation for 8250 with 32-bit mmio is needed. > > In fact, I suspect the opposite is true; that before these arm64 designs, > SPCR + 16550 + MMIO automatically meant 8-bit data width, which is why it's > unspecified in the SPCR table. > > Regards, > Peter Hurley > > > > > > The 8250_dw driver does support > > non-standard clocks specified in the DSDT. That works fine for Mustang > > and m400. > > > > So with this quick hack, v7 is working with Mustang/m400: > > > > diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c > > index 68ffc33..dade9de 100644 > > --- a/drivers/acpi/spcr.c > > +++ b/drivers/acpi/spcr.c > > @@ -37,6 +37,7 @@ int __init parse_spcr(bool earlycon) > > acpi_status status; > > char *uart; > > char *iotype; > > + int mmio; > > int baud_rate; > > int err; > > > > @@ -56,8 +57,8 @@ int __init parse_spcr(bool earlycon) > > goto done; > > } > > > > - iotype = table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY ? > > - "mmio" : "io"; > > + mmio = table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY; > > + iotype = mmio ? "mmio" : "io"; > > > > switch (table->interface_type) { > > case ACPI_DBG2_ARM_SBSA_32BIT: > > @@ -71,6 +72,8 @@ int __init parse_spcr(bool earlycon) > > case ACPI_DBG2_16550_COMPATIBLE: > > case ACPI_DBG2_16550_SUBSET: > > uart = "uart"; > > + if (mmio) > > + iotype = "mmio32"; > > break; > > default: > > err = -ENOENT; > > > > > > > > > > > We may need two 8250 subset entries, one just means no clock given, and > > > one no clock given + mmio32 only. > > > > > > Graeme > > > > > > > > > > > > > > > > > > Thank you > > > > Aleksey Makarov > > > > > > > > > > > > > > > > > > > > > > > > --Mark > > > > > > > > > > > > > > > On Thu, 2016-03-31 at 16:40 +0300, Aleksey Makarov wrote: > > > > > > > > > > > > > > > > > > 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port > > > > > > Console Redirection Table) [2] as a mandatory ACPI table that > > > > > > specifies the configuration of serial console. > > > > > > > > > > > > Move "earlycon" early_param handling to earlycon.c to parse this option once > > > > > > > > > > > > *** PATCH "ACPICA: Headers: Add new constants for the DBG2 ACPI table" > > > > > > *** IS JUST TO ENABLE BUILDING THE PATCHSET ON linux-next > > > > > > > > > > > > Patch "ACPICA: Headers: Add new constants for the DBG2 ACPI table" is required > > > > > > for the next patch. It is taken from ACPICA series [3], but it has not appeared > > > > > > in linux-next yet. > > > > > > > > > > > > Parse SPCR table, setup earlycon and add register specified console. > > > > > > > > > > > > Enable parsing this table on ARM64. Earlycon should be set up > > > > > > as early as possible. ACPI boot tables are mapped in > > > > > > arch/arm64/kernel/acpi.c:acpi_boot_table_init() called from setup_arch() > > > > > > and that's where we parse spcr. So it has to be opted-in per-arch. > > > > > > > > > > > > Implement console_match() for pl011. > > > > > > > > > > > > Based on the work by Leif Lindholm [4] > > > > > > Thanks to Peter Hurley for explaining how this should work. > > > > > > > > > > > > Should be applied to next-20160331. > > > > > > > > > > > > Tested on QEMU. SPCR support is included in QEMU's ARM mach-virt > > > > > > since 2.4 release. > > > > > > > > > > > > v7: > > > > > > - add Acked-by: Rob Herring for "of/serial: move earlycon early_param handling > > > > > > to serial" > > > > > > - call DT earlycon initialization from the arch ACPI code, not from parse_spcr() > > > > > > (Rafael J. Wysocki) > > > > > > - fix a few minor issues (Rafael J. Wysocki) > > > > > > > > > > > > v6: > > > > > > https://lkml.kernel.org/g/1458823925-19560-1-git-send-email-aleksey.makarov@linaro.org > > > > > > - add documentation for parse_spcr() functioin (Yury Norov) > > > > > > - don't initialize err variable (Yury Norov) > > > > > > - add __initdata for the earlycon_init_is_deferred flag variable > > > > > > - rename the function exported in "of/serial: move earlycon early_param handling > > > > > > to serial" to avoid clash with the function from arch/microblaze/kernel/prom.c > > > > > > - defer initialization of DT earlycon until DT/ACPI decision is made > > > > > > (Rob Herring, Peter Hurley) > > > > > > - use snprintf instead of sprintf (Andy Shevchenko) > > > > > > - drop patch that adds EARLYCON_DECLARE for pl011 as EARLYCON_DECLARE is > > > > > > equivalent to OF_EARLYCON_DECLARE for 4.6+ (Peter Hurley). This means that > > > > > > SPCR earlycon will not work on the kernels before 4.6 > > > > > > > > > > > > v5: > > > > > > https://lkml.kernel.org/g/1458643595-14719-1-git-send-email-aleksey.makarov@linaro.org > > > > > > - drop patch "serial: pl011: use ACPI SPCR to setup 32-bit access" because > > > > > > it is ugly. Also because Christopher Covington came with a better solution [5] > > > > > > - remove error message when the table is not provided by ACPI (Andy Shevchenko) > > > > > > - rewrite spcr.c following the suggestions by Peter Hurley > > > > > > - add console_match() for pl011 in a separate patch > > > > > > - add EARLYCON_DECLARE for pl011 in a separate patch > > > > > > - add patch "of/serial: move earlycon early_param handling to serial" from > > > > > > the GDB2 series > > > > > > > > > > > > v4: > > > > > > https://lkml.kernel.org/g/1456747355-15692-1-git-send-email-aleksey.makarov@linaro.org > > > > > > - drop patch "ACPI: change __init to __ref for early_acpi_os_unmap_memory()" > > > > > > ACPI developers work on a new API and asked not to do that. > > > > > > Instead, use acpi_get_table_with_size()/early_acpi_os_unmap_memory() once > > > > > > and cache the result. (Lv Zheng) > > > > > > - fix some style issues (Yury Norov) > > > > > > > > > > > > v3: > > > > > > https://lkml.kernel.org/g/1455559532-8305-1-git-send-email-aleksey.makarov@linaro.org > > > > > > > > > > > > Greg Kroah-Hartman did not like v2 so I have rewritten this patchset: > > > > > > > > > > > > - drop acpi_match() member of struct console > > > > > > - drop implementations of this member for pl011 and 8250 > > > > > > - drop the patch that renames some vars in printk.c as it is not needed anymore > > > > > > - drop patch that introduces system wide acpi_table_parse2(). > > > > > > Instead introduce a custom acpi_table_parse_spcr() in spcr.c > > > > > > > > > > > > Instead of introducing a new match_acpi() member of struct console, > > > > > > this patchset introduces a new function acpi_console_check(). > > > > > > This function is called when a new uart is registered at serial_core.c > > > > > > the same way OF code checks for console. If the registered uart is the > > > > > > console specified by SPCR table, this function calls add_preferred_console() > > > > > > > > > > > > The restrictions of this approach are: > > > > > > > > > > > > - only serial consoles can be set up > > > > > > - only consoles specified by the memory/io address can be set up > > > > > > (SPCR can specify devices by PCI id/PCI address) > > > > > > > > > > > > v2: > > > > > > https://lkml.kernel.org/g/1455299022-11641-1-git-send-email-aleksey.makarov@linaro.org > > > > > > - don't use SPCR if user specified console in command line > > > > > > - fix initialization order of newcon->index = 0 > > > > > > - rename some variables at printk.c (Joe Perches, Peter Hurley) > > > > > > - enable ACPI_SPCR_TABLE in a separate patch (Andy Shevchenko) > > > > > > - remove the retry loop for console registering (Peter Hurley). > > > > > > Instead, obtain SPCR with acpi_get_table(). That works after > > > > > > call to acpi_early_init() i. e. in any *_initcall() > > > > > > - describe design decision behind introducing acpi_match() (Peter Hurley) > > > > > > - fix compilation for x86 + ACPI (Graeme Gregory) > > > > > > - introduce DBG2 constants in a separate patch (Andy Shevchenko) > > > > > > - fix a typo in DBG2 constants (Andy Shevchenko) > > > > > > - add ACPI_DBG2_ARM_SBSA_32BIT constant (Christopher Covington) > > > > > > - add support for ACPI_DBG2_ARM_SBSA_* consoles (Christopher Covington) > > > > > > - add documentation for functions > > > > > > - add a patch that uses SPCR to find if SBSA serial driver should use 32-bit > > > > > > accessor functions (Christopher Covington) > > > > > > - change __init to __ref for early_acpi_os_unmap_memory() in a separate patch > > > > > > - introduce acpi_table_parse2() in a separate patch > > > > > > - fix fetching the SPCR table early (Mark Salter) > > > > > > - add a patch from Mark Salter that introduces support for matching 8250-based > > > > > > consoles > > > > > > > > > > > > v1: > > > > > > https://lkml.kernel.org/g/1453722324-22407-1-git-send-email-aleksey.makarov@linaro.org > > > > > > > > > > > > [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html > > > > > > [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx > > > > > > [3] https://lkml.kernel.org/g/cover.1458714002.git.lv.zheng@intel.com > > > > > > [4] https://lkml.kernel.org/g/1441716217-23786-1-git-send-email-leif.lindholm@linaro.org > > > > > > [5] https://lkml.kernel.org/g/1457415800-8799-1-git-send-email-cov@codeaurora.org > > > > > > > > > > > > Aleksey Makarov (4): > > > > > > ACPICA: Headers: Add new constants for the DBG2 ACPI table > > > > > > ACPI: parse SPCR and enable matching console > > > > > > ARM64: ACPI: enable ACPI_SPCR_TABLE > > > > > > serial: pl011: add console matching function > > > > > > > > > > > > Leif Lindholm (1): > > > > > > of/serial: move earlycon early_param handling to serial > > > > > > > > > > > > arch/arm64/Kconfig | 1 + > > > > > > arch/arm64/kernel/acpi.c | 11 +++- > > > > > > drivers/acpi/Kconfig | 3 ++ > > > > > > drivers/acpi/Makefile | 1 + > > > > > > drivers/acpi/spcr.c | 111 ++++++++++++++++++++++++++++++++++++++++ > > > > > > drivers/of/fdt.c | 11 +--- > > > > > > drivers/tty/serial/amba-pl011.c | 56 ++++++++++++++++++++ > > > > > > drivers/tty/serial/earlycon.c | 19 ++++++- > > > > > > include/acpi/actbl2.h | 7 ++- > > > > > > include/linux/acpi.h | 6 +++ > > > > > > include/linux/of_fdt.h | 2 + > > > > > > include/linux/serial_core.h | 6 +++ > > > > > > 12 files changed, 220 insertions(+), 14 deletions(-) > > > > > > create mode 100644 drivers/acpi/spcr.c > > > > > > > > > > _______________________________________________ > > > > linux-arm-kernel mailing list > > > > linux-arm-kernel@lists.infradead.org > > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index 68ffc33..dade9de 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -37,6 +37,7 @@ int __init parse_spcr(bool earlycon) acpi_status status; char *uart; char *iotype; + int mmio; int baud_rate; int err; @@ -56,8 +57,8 @@ int __init parse_spcr(bool earlycon) goto done; } - iotype = table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY ? - "mmio" : "io"; + mmio = table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY; + iotype = mmio ? "mmio" : "io"; switch (table->interface_type) { case ACPI_DBG2_ARM_SBSA_32BIT: @@ -71,6 +72,8 @@ int __init parse_spcr(bool earlycon) case ACPI_DBG2_16550_COMPATIBLE: case ACPI_DBG2_16550_SUBSET: uart = "uart"; + if (mmio) + iotype = "mmio32"; break; default: err = -ENOENT;