[PATCH 00/36] Rid W=1 issues from TTY

[PATCH 00/36] Rid W=1 issues from TTY

[Lee Jones]

This set is part of a larger effort attempting to clean-up W=1
kernel builds, which are currently overwhelmingly riddled with
niggly little warnings.

Lee Jones (36):
  tty: serdev: core: Remove unused variable 'dummy'
  tty: serdev: core: Provide missing description for 'owner'
  tty: tty_baudrate: Add missing description for 'tty'
  tty: tty_io: Move 'tty_sysctl_init's prototype to shared space
  tty: tty_buffer: Add missing description for 'limit'
  tty: tty_port: Demote obvious abuse of kernel-doc formatting
  tty: tty_jobctrl: Add missing function parameter descriptions
  tty: tty_ldisc: Fix some kernel-doc related misdemeanours
  tty: vt: consolemap: Demote weakly documented function header
  tty: n_tty: Add 2 missing parameter descriptions
  tty: serial: jsm: jsm_cls: Remove unused variable 'discard'
  tty: tty_io: Fix some kernel-doc issues
  tty: serial: 8250: 8250_port: Staticify functions referenced by
    pointers
  tty: serial: 8250: serial_cs: Remove unused/unchecked variable 'err'
  tty: tty_audit: Demote non-conformant kernel-doc headers
  tty: pty: Provide descriptions for the 'file' parameters
  tty: serial: amba-pl011: Mark 'sbsa_uart_acpi_match' as __maybe_unused
  tty: n_gsm: Demote obvious abuse of kernel-doc and supply other
    missing docss
  tty: serial: lpc32xx_hs: Remove unused variable 'tmp'
  tty: serial: msm_serial: Remove set but unused variable 'status'
  tty: serial: ifx6x60: Fix function documentation headers
  tty: serial: xilinx_uartps: Supply description for missing member
    'cts_override'
  tty: synclink_gt: Demote one kernel-doc header and repair another
  tty: serial: serial-tegra: Struct headers should start with 'struct
    <name>'
  tty: serial: sifive: Struct headers should start with 'struct <name>'
  tty: synclinkmp: Add missing description for function param 'txqueue'
  tty: synclinkmp: Mark never checked 'readval' as __always_unused
  tty: serial: stm32-usart: Remove set but unused 'cookie' variables
  tty: tty_ldisc: Supply missing description for 'tty_ldisc_get's 'tty'
    param
  tty: serial: serial-tegra: Provide some missing struct member
    descriptions
  powerpc: asm: hvconsole: Move 'hvc_vio_init_early's prototype to
    shared location
  tty: hvc: hvc_vio: Staticify function invoked only by reference
  tty: hvc: hvc_opal: Staticify function invoked by reference
  tty: serial: pmac_zilog: Make disposable variable __always_unused
  tty: synclink: Mark disposable variables as __always_unused
  tty: synclink: Provide missing description for 'hdlcdev_tx_timeout's
    'txqueue' param

 arch/powerpc/include/asm/hvconsole.h     |  3 +++
 arch/powerpc/platforms/pseries/pseries.h |  3 ---
 arch/powerpc/platforms/pseries/setup.c   |  1 +
 drivers/tty/hvc/hvc_opal.c               |  2 +-
 drivers/tty/hvc/hvc_vio.c                |  2 +-
 drivers/tty/n_gsm.c                      |  4 +++-
 drivers/tty/n_tty.c                      |  2 ++
 drivers/tty/pty.c                        |  2 ++
 drivers/tty/serdev/core.c                |  6 ++----
 drivers/tty/serial/8250/8250_port.c      |  4 ++--
 drivers/tty/serial/8250/serial_cs.c      |  9 +++------
 drivers/tty/serial/amba-pl011.c          |  2 +-
 drivers/tty/serial/ifx6x60.c             |  3 ++-
 drivers/tty/serial/jsm/jsm_cls.c         |  4 +---
 drivers/tty/serial/lpc32xx_hs.c          |  3 +--
 drivers/tty/serial/msm_serial.c          |  3 +--
 drivers/tty/serial/pmac_zilog.h          |  2 +-
 drivers/tty/serial/serial-tegra.c        |  7 ++++++-
 drivers/tty/serial/sifive.c              |  3 ++-
 drivers/tty/serial/stm32-usart.c         |  6 ++----
 drivers/tty/serial/xilinx_uartps.c       |  1 +
 drivers/tty/synclink.c                   |  5 +++--
 drivers/tty/synclink_gt.c                |  3 ++-
 drivers/tty/synclinkmp.c                 |  3 ++-
 drivers/tty/tty_audit.c                  | 12 ++++++------
 drivers/tty/tty_baudrate.c               |  1 +
 drivers/tty/tty_buffer.c                 |  1 +
 drivers/tty/tty_io.c                     | 12 +++++++-----
 drivers/tty/tty_jobctrl.c                |  3 +++
 drivers/tty/tty_ldisc.c                  | 11 ++++++-----
 drivers/tty/tty_port.c                   |  4 ++--
 drivers/tty/vt/consolemap.c              |  3 +--
 include/linux/tty.h                      |  1 +
 33 files changed, 73 insertions(+), 58 deletions(-)

Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: "Andrew J. Kroll" <ag784@freenet.buffalo.edu>
Cc: Andrew Morton <andrewm@uow.edu.eu>
Cc: Andy Gross <agross@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bill Hawes <whawes@star.net>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: "C. Scott Ananian" <cananian@alumni.princeton.edu>
Cc: "David A. Hinds" <dahinds@users.sourceforge.net>
Cc: dri-devel@lists.freedesktop.org
Cc: Filip Aben <f.aben@option.com>
Cc: Gerald Baeza <gerald.baeza@st.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jakub Jelinek <jj@ultra.linux.cz>
Cc: Jan Dumon <j.dumon@option.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Joseph Barrow <d.barow@option.com>
Cc: -- <julian@uhunix.uhcc.hawaii.edu>
Cc: Kevin Wells <kevin.wells@nxp.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-serial@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-tegra@vger.kernel.org
Cc: Marko Kohtala <Marko.Kohtala@hut.fi>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Mike Hudson <Exoray@isys.ca>
Cc: Miloslav Trmac <mitr@redhat.com>
Cc: Nick Holloway <alfie@dcs.warwick.ac.uk>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: paulkf@microgate.com
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: processes-Sapan Bhatia <sapan@corewars.org>
Cc: Robert Love <rlove@google.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Roland Stigge <stigge@antcom.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Russ Gorby <russ.gorby@intel.com>
Cc: Stanislav Voronyi <stas@cnti.uanet.kharkov.ua>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
-- 
2.25.1

[PATCH 31/36] powerpc: asm: hvconsole: Move 'hvc_vio_init_early's prototype to shared location

[Lee Jones]

Fixes the following W=1 kernel build warning(s):

 drivers/tty/hvc/hvc_vio.c:385:13: warning: no previous prototype for ‘hvc_vio_init_early’ [-Wmissing-prototypes]
 385 | void __init hvc_vio_init_early(void)
 | ^~~~~~~~~~~~~~~~~~

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/powerpc/include/asm/hvconsole.h     | 3 +++
 arch/powerpc/platforms/pseries/pseries.h | 3 ---
 arch/powerpc/platforms/pseries/setup.c   | 1 +
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/hvconsole.h b/arch/powerpc/include/asm/hvconsole.h
index 999ed5ac90531..936a1ee1ac786 100644
--- a/arch/powerpc/include/asm/hvconsole.h
+++ b/arch/powerpc/include/asm/hvconsole.h
@@ -24,5 +24,8 @@
 extern int hvc_get_chars(uint32_t vtermno, char *buf, int count);
 extern int hvc_put_chars(uint32_t vtermno, const char *buf, int count);
 
+/* Provided by HVC VIO */
+extern void hvc_vio_init_early(void);
+
 #endif /* __KERNEL__ */
 #endif /* _PPC64_HVCONSOLE_H */
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 13fa370a87e4e..7be5b054dfc36 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -43,9 +43,6 @@ extern void pSeries_final_fixup(void);
 /* Poweron flag used for enabling auto ups restart */
 extern unsigned long rtas_poweron_auto;
 
-/* Provided by HVC VIO */
-extern void hvc_vio_init_early(void);
-
 /* Dynamic logical Partitioning/Mobility */
 extern void dlpar_free_cc_nodes(struct device_node *);
 extern void dlpar_free_cc_property(struct property *);
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 633c45ec406da..6999b83f06612 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -71,6 +71,7 @@
 #include <asm/swiotlb.h>
 #include <asm/svm.h>
 #include <asm/dtl.h>
+#include <asm/hvconsole.h>
 
 #include "pseries.h"
 #include "../../../../drivers/pci/pci.h"
-- 
2.25.1

[PATCH 32/36] tty: hvc: hvc_vio: Staticify function invoked only by reference

[Lee Jones]

Fixes the following W=1 kernel build warning(s):

 drivers/tty/hvc/hvc_vio.c:181:6: warning: no previous prototype for ‘hvterm_hvsi_hangup’ [-Wmissing-prototypes]
 181 | void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
 | ^~~~~~~~~~~~~~~~~~

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/tty/hvc/hvc_vio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
index 7af54d6ed5b84..798f27f40cc2d 100644
--- a/drivers/tty/hvc/hvc_vio.c
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -178,7 +178,7 @@ static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
 	notifier_del_irq(hp, data);
 }
 
-void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
+static void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
 {
 	struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 
-- 
2.25.1

[PATCH 33/36] tty: hvc: hvc_opal: Staticify function invoked by reference

[Lee Jones]

Fixes the following W=1 kernel build warning(s):

 drivers/tty/hvc/hvc_opal.c:106:6: warning: no previous prototype for ‘hvc_opal_hvsi_hangup’ [-Wmissing-prototypes]

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/tty/hvc/hvc_opal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index c66412566efce..056ae21a51214 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -103,7 +103,7 @@ static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
 	notifier_del_irq(hp, data);
 }
 
-void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
+static void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
 {
 	struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 
-- 
2.25.1

[PATCH 34/36] tty: serial: pmac_zilog: Make disposable variable __always_unused

[Lee Jones]

Fixes the following W=1 kernel build warning(s):

 drivers/tty/serial/pmac_zilog.h:365:58: warning: variable ‘garbage’ set but not used [-Wunused-but-set-variable]

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-serial@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/tty/serial/pmac_zilog.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/pmac_zilog.h b/drivers/tty/serial/pmac_zilog.h
index bb874e76810e0..968aec7c1cf82 100644
--- a/drivers/tty/serial/pmac_zilog.h
+++ b/drivers/tty/serial/pmac_zilog.h
@@ -362,7 +362,7 @@ static inline void zssync(struct uart_pmac_port *port)
 
 /* Misc macros */
 #define ZS_CLEARERR(port)    (write_zsreg(port, 0, ERR_RES))
-#define ZS_CLEARFIFO(port)   do { volatile unsigned char garbage; \
+#define ZS_CLEARFIFO(port)   do { volatile unsigned char __always_unused garbage; \
 				     garbage = read_zsdata(port); \
 				     garbage = read_zsdata(port); \
 				     garbage = read_zsdata(port); \
-- 
2.25.1

Re: [PATCH 31/36] powerpc: asm: hvconsole: Move 'hvc_vio_init_early's prototype to shared location

[Michael Ellerman]

Lee Jones <lee.jones@linaro.org> writes:
> Fixes the following W=1 kernel build warning(s):
>
>  drivers/tty/hvc/hvc_vio.c:385:13: warning: no previous prototype for ‘hvc_vio_init_early’ [-Wmissing-prototypes]
>  385 | void __init hvc_vio_init_early(void)
>  | ^~~~~~~~~~~~~~~~~~
>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
>  arch/powerpc/include/asm/hvconsole.h     | 3 +++
>  arch/powerpc/platforms/pseries/pseries.h | 3 ---
>  arch/powerpc/platforms/pseries/setup.c   | 1 +
>  3 files changed, 4 insertions(+), 3 deletions(-)

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

> diff --git a/arch/powerpc/include/asm/hvconsole.h b/arch/powerpc/include/asm/hvconsole.h
> index 999ed5ac90531..936a1ee1ac786 100644
> --- a/arch/powerpc/include/asm/hvconsole.h
> +++ b/arch/powerpc/include/asm/hvconsole.h
> @@ -24,5 +24,8 @@
>  extern int hvc_get_chars(uint32_t vtermno, char *buf, int count);
>  extern int hvc_put_chars(uint32_t vtermno, const char *buf, int count);
>  
> +/* Provided by HVC VIO */
> +extern void hvc_vio_init_early(void);

extern isn't needed, but don't feel you need to respin just to drop it.

cheers

Re: [PATCH 34/36] tty: serial: pmac_zilog: Make disposable variable __always_unused

[Christophe Leroy]

Le 04/11/2020 à 20:35, Lee Jones a écrit :
> Fixes the following W=1 kernel build warning(s):
> 
>   drivers/tty/serial/pmac_zilog.h:365:58: warning: variable ‘garbage’ set but not used [-Wunused-but-set-variable]

Explain how you are fixing this warning.

Setting  __always_unused is usually not the good solution for fixing this warning, but here I guess 
this is likely the good solution. But it should be explained why.

Christophe


> 
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linux-serial@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
>   drivers/tty/serial/pmac_zilog.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/pmac_zilog.h b/drivers/tty/serial/pmac_zilog.h
> index bb874e76810e0..968aec7c1cf82 100644
> --- a/drivers/tty/serial/pmac_zilog.h
> +++ b/drivers/tty/serial/pmac_zilog.h
> @@ -362,7 +362,7 @@ static inline void zssync(struct uart_pmac_port *port)
>   
>   /* Misc macros */
>   #define ZS_CLEARERR(port)    (write_zsreg(port, 0, ERR_RES))
> -#define ZS_CLEARFIFO(port)   do { volatile unsigned char garbage; \
> +#define ZS_CLEARFIFO(port)   do { volatile unsigned char __always_unused garbage; \
>   				     garbage = read_zsdata(port); \
>   				     garbage = read_zsdata(port); \
>   				     garbage = read_zsdata(port); \
> 

Re: [PATCH 31/36] powerpc: asm: hvconsole: Move 'hvc_vio_init_early's prototype to shared location

[Christophe Leroy]

Le 04/11/2020 à 20:35, Lee Jones a écrit :
> Fixes the following W=1 kernel build warning(s):
> 
>   drivers/tty/hvc/hvc_vio.c:385:13: warning: no previous prototype for ‘hvc_vio_init_early’ [-Wmissing-prototypes]
>   385 | void __init hvc_vio_init_early(void)
>   | ^~~~~~~~~~~~~~~~~~
> 
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
>   arch/powerpc/include/asm/hvconsole.h     | 3 +++
>   arch/powerpc/platforms/pseries/pseries.h | 3 ---
>   arch/powerpc/platforms/pseries/setup.c   | 1 +
>   3 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/hvconsole.h b/arch/powerpc/include/asm/hvconsole.h
> index 999ed5ac90531..936a1ee1ac786 100644
> --- a/arch/powerpc/include/asm/hvconsole.h
> +++ b/arch/powerpc/include/asm/hvconsole.h
> @@ -24,5 +24,8 @@
>   extern int hvc_get_chars(uint32_t vtermno, char *buf, int count);
>   extern int hvc_put_chars(uint32_t vtermno, const char *buf, int count);
>   
> +/* Provided by HVC VIO */
> +extern void hvc_vio_init_early(void);
> +

Declaring a prototype 'extern' is pointless. Don't add new misuse of 'extern' keyword.


>   #endif /* __KERNEL__ */
>   #endif /* _PPC64_HVCONSOLE_H */
> diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
> index 13fa370a87e4e..7be5b054dfc36 100644
> --- a/arch/powerpc/platforms/pseries/pseries.h
> +++ b/arch/powerpc/platforms/pseries/pseries.h
> @@ -43,9 +43,6 @@ extern void pSeries_final_fixup(void);
>   /* Poweron flag used for enabling auto ups restart */
>   extern unsigned long rtas_poweron_auto;
>   
> -/* Provided by HVC VIO */
> -extern void hvc_vio_init_early(void);
> -
>   /* Dynamic logical Partitioning/Mobility */
>   extern void dlpar_free_cc_nodes(struct device_node *);
>   extern void dlpar_free_cc_property(struct property *);
> diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
> index 633c45ec406da..6999b83f06612 100644
> --- a/arch/powerpc/platforms/pseries/setup.c
> +++ b/arch/powerpc/platforms/pseries/setup.c
> @@ -71,6 +71,7 @@
>   #include <asm/swiotlb.h>
>   #include <asm/svm.h>
>   #include <asm/dtl.h>
> +#include <asm/hvconsole.h>
>   
>   #include "pseries.h"
>   #include "../../../../drivers/pci/pci.h"
> 

Christophe

Re: [PATCH 34/36] tty: serial: pmac_zilog: Make disposable variable __always_unused

[Jiri Slaby]

On 05. 11. 20, 8:04, Christophe Leroy wrote:
> 
> 
> Le 04/11/2020 à 20:35, Lee Jones a écrit :
>> Fixes the following W=1 kernel build warning(s):
>>
>>   drivers/tty/serial/pmac_zilog.h:365:58: warning: variable ‘garbage’ 
>> set but not used [-Wunused-but-set-variable]
> 
> Explain how you are fixing this warning.
> 
> Setting  __always_unused is usually not the good solution for fixing 
> this warning, but here I guess this is likely the good solution. But it 
> should be explained why.

Or, why is the "garbage =" needed in the first place? read_zsdata is not 
defined with __warn_unused_result__. And even if it was, would 
(void)!read_zsdata(port) fix it?

>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: Jiri Slaby <jirislaby@kernel.org>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: linux-serial@vger.kernel.org
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Signed-off-by: Lee Jones <lee.jones@linaro.org>
>> ---
>>   drivers/tty/serial/pmac_zilog.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/tty/serial/pmac_zilog.h 
>> b/drivers/tty/serial/pmac_zilog.h
>> index bb874e76810e0..968aec7c1cf82 100644
>> --- a/drivers/tty/serial/pmac_zilog.h
>> +++ b/drivers/tty/serial/pmac_zilog.h
>> @@ -362,7 +362,7 @@ static inline void zssync(struct uart_pmac_port 
>> *port)
>>   /* Misc macros */
>>   #define ZS_CLEARERR(port)    (write_zsreg(port, 0, ERR_RES))
>> -#define ZS_CLEARFIFO(port)   do { volatile unsigned char garbage; \
>> +#define ZS_CLEARFIFO(port)   do { volatile unsigned char 
>> __always_unused garbage; \
>>                        garbage = read_zsdata(port); \
>>                        garbage = read_zsdata(port); \
>>                        garbage = read_zsdata(port); \
>>

thanks,
-- 
js

Re: [PATCH 34/36] tty: serial: pmac_zilog: Make disposable variable __always_unused

[Lee Jones]

On Thu, 05 Nov 2020, Jiri Slaby wrote:

> On 05. 11. 20, 8:04, Christophe Leroy wrote:
> > 
> > 
> > Le 04/11/2020 à 20:35, Lee Jones a écrit :
> > > Fixes the following W=1 kernel build warning(s):
> > > 
> > >   drivers/tty/serial/pmac_zilog.h:365:58: warning: variable
> > > ‘garbage’ set but not used [-Wunused-but-set-variable]
> > 
> > Explain how you are fixing this warning.
> > 
> > Setting  __always_unused is usually not the good solution for fixing
> > this warning, but here I guess this is likely the good solution. But it
> > should be explained why.

There are normally 3 ways to fix this warning;

 - Start using/checking the variable/result
 - Remove the variable
 - Mark it as __{always,maybe}_unused

The later just tells the compiler that not checking the resultant
value is intentional.  There are some functions (as Jiri mentions
below) which are marked as '__must_check' which *require* a dummy
(garbage) variable to be used.

> Or, why is the "garbage =" needed in the first place? read_zsdata is not
> defined with __warn_unused_result__.

I used '__always_used' here for fear of breaking something.

However, if it's safe to remove it, then all the better.

> And even if it was, would (void)!read_zsdata(port) fix it?

That's hideous. :D

*Much* better to just use '__always_used' in that use-case.

> > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > Cc: Jiri Slaby <jirislaby@kernel.org>
> > > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > > Cc: Paul Mackerras <paulus@samba.org>
> > > Cc: linux-serial@vger.kernel.org
> > > Cc: linuxppc-dev@lists.ozlabs.org
> > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > > ---
> > >   drivers/tty/serial/pmac_zilog.h | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/tty/serial/pmac_zilog.h
> > > b/drivers/tty/serial/pmac_zilog.h
> > > index bb874e76810e0..968aec7c1cf82 100644
> > > --- a/drivers/tty/serial/pmac_zilog.h
> > > +++ b/drivers/tty/serial/pmac_zilog.h
> > > @@ -362,7 +362,7 @@ static inline void zssync(struct uart_pmac_port
> > > *port)
> > >   /* Misc macros */
> > >   #define ZS_CLEARERR(port)    (write_zsreg(port, 0, ERR_RES))
> > > -#define ZS_CLEARFIFO(port)   do { volatile unsigned char garbage; \
> > > +#define ZS_CLEARFIFO(port)   do { volatile unsigned char
> > > __always_unused garbage; \
> > >                        garbage = read_zsdata(port); \
> > >                        garbage = read_zsdata(port); \
> > >                        garbage = read_zsdata(port); \
> > > 
> 
> thanks,

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH 31/36] powerpc: asm: hvconsole: Move 'hvc_vio_init_early's prototype to shared location

[Lee Jones]

On Thu, 05 Nov 2020, Christophe Leroy wrote:

> 
> 
> Le 04/11/2020 à 20:35, Lee Jones a écrit :
> > Fixes the following W=1 kernel build warning(s):
> > 
> >   drivers/tty/hvc/hvc_vio.c:385:13: warning: no previous prototype for ‘hvc_vio_init_early’ [-Wmissing-prototypes]
> >   385 | void __init hvc_vio_init_early(void)
> >   | ^~~~~~~~~~~~~~~~~~
> > 
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > ---
> >   arch/powerpc/include/asm/hvconsole.h     | 3 +++
> >   arch/powerpc/platforms/pseries/pseries.h | 3 ---
> >   arch/powerpc/platforms/pseries/setup.c   | 1 +
> >   3 files changed, 4 insertions(+), 3 deletions(-)
> > 
> > diff --git a/arch/powerpc/include/asm/hvconsole.h b/arch/powerpc/include/asm/hvconsole.h
> > index 999ed5ac90531..936a1ee1ac786 100644
> > --- a/arch/powerpc/include/asm/hvconsole.h
> > +++ b/arch/powerpc/include/asm/hvconsole.h
> > @@ -24,5 +24,8 @@
> >   extern int hvc_get_chars(uint32_t vtermno, char *buf, int count);
> >   extern int hvc_put_chars(uint32_t vtermno, const char *buf, int count);
> > +/* Provided by HVC VIO */
> > +extern void hvc_vio_init_early(void);
> > +
> 
> Declaring a prototype 'extern' is pointless. Don't add new misuse of 'extern' keyword.

No new code (misuse or otherwise) is being added in this patch.

It's just moved from one place to another.

I can also strip out 'extern' if it's preferred.

> >   #endif /* __KERNEL__ */
> >   #endif /* _PPC64_HVCONSOLE_H */
> > diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
> > index 13fa370a87e4e..7be5b054dfc36 100644
> > --- a/arch/powerpc/platforms/pseries/pseries.h
> > +++ b/arch/powerpc/platforms/pseries/pseries.h
> > @@ -43,9 +43,6 @@ extern void pSeries_final_fixup(void);
> >   /* Poweron flag used for enabling auto ups restart */
> >   extern unsigned long rtas_poweron_auto;
> > -/* Provided by HVC VIO */
> > -extern void hvc_vio_init_early(void);
> > -
> >   /* Dynamic logical Partitioning/Mobility */
> >   extern void dlpar_free_cc_nodes(struct device_node *);
> >   extern void dlpar_free_cc_property(struct property *);
> > diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
> > index 633c45ec406da..6999b83f06612 100644
> > --- a/arch/powerpc/platforms/pseries/setup.c
> > +++ b/arch/powerpc/platforms/pseries/setup.c
> > @@ -71,6 +71,7 @@
> >   #include <asm/swiotlb.h>
> >   #include <asm/svm.h>
> >   #include <asm/dtl.h>
> > +#include <asm/hvconsole.h>
> >   #include "pseries.h"
> >   #include "../../../../drivers/pci/pci.h"
> > 
> 
> Christophe

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH 31/36] powerpc: asm: hvconsole: Move 'hvc_vio_init_early's prototype to shared location

[Lee Jones]

On Thu, 05 Nov 2020, Michael Ellerman wrote:

> Lee Jones <lee.jones@linaro.org> writes:
> > Fixes the following W=1 kernel build warning(s):
> >
> >  drivers/tty/hvc/hvc_vio.c:385:13: warning: no previous prototype for ‘hvc_vio_init_early’ [-Wmissing-prototypes]
> >  385 | void __init hvc_vio_init_early(void)
> >  | ^~~~~~~~~~~~~~~~~~
> >
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Signed-off-by: Lee Jones <lee.jones@linaro.org>
> > ---
> >  arch/powerpc/include/asm/hvconsole.h     | 3 +++
> >  arch/powerpc/platforms/pseries/pseries.h | 3 ---
> >  arch/powerpc/platforms/pseries/setup.c   | 1 +
> >  3 files changed, 4 insertions(+), 3 deletions(-)
> 
> Acked-by: Michael Ellerman <mpe@ellerman.id.au>

Thanks.

> > diff --git a/arch/powerpc/include/asm/hvconsole.h b/arch/powerpc/include/asm/hvconsole.h
> > index 999ed5ac90531..936a1ee1ac786 100644
> > --- a/arch/powerpc/include/asm/hvconsole.h
> > +++ b/arch/powerpc/include/asm/hvconsole.h
> > @@ -24,5 +24,8 @@
> >  extern int hvc_get_chars(uint32_t vtermno, char *buf, int count);
> >  extern int hvc_put_chars(uint32_t vtermno, const char *buf, int count);
> >  
> > +/* Provided by HVC VIO */
> > +extern void hvc_vio_init_early(void);
> 
> extern isn't needed, but don't feel you need to respin just to drop it.

That's fine.  I don't mind re-spinning.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH 34/36] tty: serial: pmac_zilog: Make disposable variable __always_unused

[Jiri Slaby]

On 05. 11. 20, 9:36, Lee Jones wrote:
> On Thu, 05 Nov 2020, Jiri Slaby wrote:
> 
>> On 05. 11. 20, 8:04, Christophe Leroy wrote:
>>>
>>>
>>> Le 04/11/2020 à 20:35, Lee Jones a écrit :
>>>> Fixes the following W=1 kernel build warning(s):
>>>>
>>>>    drivers/tty/serial/pmac_zilog.h:365:58: warning: variable
>>>> ‘garbage’ set but not used [-Wunused-but-set-variable]
>>>
>>> Explain how you are fixing this warning.
>>>
>>> Setting  __always_unused is usually not the good solution for fixing
>>> this warning, but here I guess this is likely the good solution. But it
>>> should be explained why.
> 
> There are normally 3 ways to fix this warning;
> 
>   - Start using/checking the variable/result
>   - Remove the variable
>   - Mark it as __{always,maybe}_unused
> 
> The later just tells the compiler that not checking the resultant
> value is intentional.  There are some functions (as Jiri mentions
> below) which are marked as '__must_check' which *require* a dummy
> (garbage) variable to be used.
> 
>> Or, why is the "garbage =" needed in the first place? read_zsdata is not
>> defined with __warn_unused_result__.
> 
> I used '__always_used' here for fear of breaking something.
> 
> However, if it's safe to remove it, then all the better.

Yes please -- this "garbage" is one of the examples of volatile misuses. 
If readb didn't work on volatile pointer, marking the return variable as 
volatile wouldn't save it.

>> And even if it was, would (void)!read_zsdata(port) fix it?
> 
> That's hideous. :D

Sure, marking reads as must_check would be insane.

> *Much* better to just use '__always_used' in that use-case.

Then using a dummy variable to fool must_check must mean must_check is 
used incorrectly, no :)? But there are always exceptions…

thanks,
-- 
js
suse labs

Re: [PATCH 34/36] tty: serial: pmac_zilog: Make disposable variable __always_unused

[Lee Jones]

On Thu, 05 Nov 2020, Jiri Slaby wrote:

> On 05. 11. 20, 9:36, Lee Jones wrote:
> > On Thu, 05 Nov 2020, Jiri Slaby wrote:
> > 
> > > On 05. 11. 20, 8:04, Christophe Leroy wrote:
> > > > 
> > > > 
> > > > Le 04/11/2020 à 20:35, Lee Jones a écrit :
> > > > > Fixes the following W=1 kernel build warning(s):
> > > > > 
> > > > >    drivers/tty/serial/pmac_zilog.h:365:58: warning: variable
> > > > > ‘garbage’ set but not used [-Wunused-but-set-variable]
> > > > 
> > > > Explain how you are fixing this warning.
> > > > 
> > > > Setting  __always_unused is usually not the good solution for fixing
> > > > this warning, but here I guess this is likely the good solution. But it
> > > > should be explained why.
> > 
> > There are normally 3 ways to fix this warning;
> > 
> >   - Start using/checking the variable/result
> >   - Remove the variable
> >   - Mark it as __{always,maybe}_unused
> > 
> > The later just tells the compiler that not checking the resultant
> > value is intentional.  There are some functions (as Jiri mentions
> > below) which are marked as '__must_check' which *require* a dummy
> > (garbage) variable to be used.
> > 
> > > Or, why is the "garbage =" needed in the first place? read_zsdata is not
> > > defined with __warn_unused_result__.
> > 
> > I used '__always_used' here for fear of breaking something.
> > 
> > However, if it's safe to remove it, then all the better.
> 
> Yes please -- this "garbage" is one of the examples of volatile misuses. If
> readb didn't work on volatile pointer, marking the return variable as
> volatile wouldn't save it.
> 
> > > And even if it was, would (void)!read_zsdata(port) fix it?
> > 
> > That's hideous. :D
> 
> Sure, marking reads as must_check would be insane.
> 
> > *Much* better to just use '__always_used' in that use-case.
> 
> Then using a dummy variable to fool must_check must mean must_check is used
> incorrectly, no :)? But there are always exceptions…

Agreed on all points.

Will fix.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH 00/36] Rid W=1 issues from TTY

[Greg Kroah-Hartman]

On Wed, Nov 04, 2020 at 07:35:13PM +0000, Lee Jones wrote:
> This set is part of a larger effort attempting to clean-up W=1
> kernel builds, which are currently overwhelmingly riddled with
> niggly little warnings.

Many of these now applied, please update the series against my
tty-testing branch and resend the rest.

thanks,

greg k-h

[PATCH v2 31/36] powerpc: asm: hvconsole: Move 'hvc_vio_init_early's prototype to shared location

[Lee Jones]

Fixes the following W=1 kernel build warning(s):

 drivers/tty/hvc/hvc_vio.c:385:13: warning: no previous prototype for ‘hvc_vio_init_early’ [-Wmissing-prototypes]
 385 | void __init hvc_vio_init_early(void)
 | ^~~~~~~~~~~~~~~~~~

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---

v2:
- Removed 'extern' keyword

 arch/powerpc/include/asm/hvconsole.h     | 3 +++
 arch/powerpc/platforms/pseries/pseries.h | 3 ---
 arch/powerpc/platforms/pseries/setup.c   | 1 +
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/hvconsole.h b/arch/powerpc/include/asm/hvconsole.h
index 999ed5ac90531..ccb2034506f0f 100644
--- a/arch/powerpc/include/asm/hvconsole.h
+++ b/arch/powerpc/include/asm/hvconsole.h
@@ -24,5 +24,8 @@
 extern int hvc_get_chars(uint32_t vtermno, char *buf, int count);
 extern int hvc_put_chars(uint32_t vtermno, const char *buf, int count);
 
+/* Provided by HVC VIO */
+void hvc_vio_init_early(void);
+
 #endif /* __KERNEL__ */
 #endif /* _PPC64_HVCONSOLE_H */
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 593840847cd3d..693f58d784b5b 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -43,9 +43,6 @@ extern void pSeries_final_fixup(void);
 /* Poweron flag used for enabling auto ups restart */
 extern unsigned long rtas_poweron_auto;
 
-/* Provided by HVC VIO */
-extern void hvc_vio_init_early(void);
-
 /* Dynamic logical Partitioning/Mobility */
 extern void dlpar_free_cc_nodes(struct device_node *);
 extern void dlpar_free_cc_property(struct property *);
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 090c13f6c8815..b5513eefd12c9 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -71,6 +71,7 @@
 #include <asm/swiotlb.h>
 #include <asm/svm.h>
 #include <asm/dtl.h>
+#include <asm/hvconsole.h>
 
 #include "pseries.h"
 #include "../../../../drivers/pci/pci.h"
-- 
2.25.1