| Message ID | 20200827144112.v2.1.I6981f9a9f0c12e60f8038f3b574184f8ffc1b9b5@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] Input: i8042 - Prevent intermixing i8042 commands | expand |
Hi, Quick self intro: I have take over drivers/platform/x86 maintainership from Andy; and I'm working my way through the backlog of old patches in patchwork: https://patchwork.kernel.org/project/platform-driver-x86/list/ On 8/27/20 10:41 PM, Raul E Rangel wrote: > The i8042_mutex must be held by writers of the AUX and KBD ports, as > well as users of i8042_command. There were a lot of users of > i8042_command that were not calling i8042_lock_chip/i8042_unlock_chip. > This resulted in i8042_commands being issues in between PS/2 > transactions. > > This change moves the mutex lock into i8042_command and removes the > burden of locking the mutex from the callers. > > It is expected that the i8042_mutex is locked before calling > i8042_aux_write or i8042_kbd_write. This is currently done by the PS/2 > layer via ps2_begin_command and ps2_end_command. Other modules > (serio_raw) do not currently lock the mutex, so there is still a > possibility for intermixed commands. > > Link: https://lore.kernel.org/linux-input/CAHQZ30ANTeM-pgdYZ4AbgxsnevBJnJgKZ1Kg+Uy8oSXZUvz=og@mail.gmail.com > Signed-off-by: Raul E Rangel <rrangel@chromium.org> Patch looks good to me, you can add my: Reviewed-by: Hans de Goede <hdegoede@redhat.com> (for both the drivers/platform/x86 bits and in general). Dmitry, feel free to merge this through the input tree, I don't expect the touched pdx86 parts to see any changes this cycle. Regards, Hans > --- > Tested this on a device with only a PS/2 keyboard. I was able to do > 1200+ suspend/resume cycles. > > Also tested this on a device with a PS/2 keyboard and a PS/2 mouse. > I was able to do 250+ iterations with out problems. > > Changes in v2: > - Fixed bad indent > - Added Link: tag > - Removed left over rc variable > > drivers/input/serio/i8042.c | 29 ++++++++++++++--------------- > drivers/leds/leds-clevo-mail.c | 9 --------- > drivers/platform/x86/acer-wmi.c | 2 -- > drivers/platform/x86/amilo-rfkill.c | 6 +----- > include/linux/i8042.h | 10 ---------- > 5 files changed, 15 insertions(+), 41 deletions(-) > > diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c > index 0dddf273afd94..65ca6b47f41e8 100644 > --- a/drivers/input/serio/i8042.c > +++ b/drivers/input/serio/i8042.c > @@ -137,8 +137,7 @@ static DEFINE_SPINLOCK(i8042_lock); > > /* > * Writers to AUX and KBD ports as well as users issuing i8042_command > - * directly should acquire i8042_mutex (by means of calling > - * i8042_lock_chip() and i8042_unlock_ship() helpers) to ensure that > + * directly should acquire i8042_mutex to ensure that > * they do not disturb each other (unfortunately in many i8042 > * implementations write to one of the ports will immediately abort > * command that is being processed by another port). > @@ -173,18 +172,6 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id); > static bool (*i8042_platform_filter)(unsigned char data, unsigned char str, > struct serio *serio); > > -void i8042_lock_chip(void) > -{ > - mutex_lock(&i8042_mutex); > -} > -EXPORT_SYMBOL(i8042_lock_chip); > - > -void i8042_unlock_chip(void) > -{ > - mutex_unlock(&i8042_mutex); > -} > -EXPORT_SYMBOL(i8042_unlock_chip); > - > int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str, > struct serio *serio)) > { > @@ -343,10 +330,14 @@ int i8042_command(unsigned char *param, int command) > unsigned long flags; > int retval; > > + mutex_lock(&i8042_mutex); > + > spin_lock_irqsave(&i8042_lock, flags); > retval = __i8042_command(param, command); > spin_unlock_irqrestore(&i8042_lock, flags); > > + mutex_unlock(&i8042_mutex); > + > return retval; > } > EXPORT_SYMBOL(i8042_command); > @@ -379,10 +370,18 @@ static int i8042_kbd_write(struct serio *port, unsigned char c) > static int i8042_aux_write(struct serio *serio, unsigned char c) > { > struct i8042_port *port = serio->port_data; > + unsigned long flags; > + int retval = 0; > + > + spin_lock_irqsave(&i8042_lock, flags); > > - return i8042_command(&c, port->mux == -1 ? > + retval = __i8042_command(&c, port->mux == -1 ? > I8042_CMD_AUX_SEND : > I8042_CMD_MUX_SEND + port->mux); > + > + spin_unlock_irqrestore(&i8042_lock, flags); > + > + return retval; > } > > > diff --git a/drivers/leds/leds-clevo-mail.c b/drivers/leds/leds-clevo-mail.c > index f512e99b976b1..6c3d7e54f95cf 100644 > --- a/drivers/leds/leds-clevo-mail.c > +++ b/drivers/leds/leds-clevo-mail.c > @@ -95,17 +95,12 @@ MODULE_DEVICE_TABLE(dmi, clevo_mail_led_dmi_table); > static void clevo_mail_led_set(struct led_classdev *led_cdev, > enum led_brightness value) > { > - i8042_lock_chip(); > - > if (value == LED_OFF) > i8042_command(NULL, CLEVO_MAIL_LED_OFF); > else if (value <= LED_HALF) > i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ); > else > i8042_command(NULL, CLEVO_MAIL_LED_BLINK_1HZ); > - > - i8042_unlock_chip(); > - > } > > static int clevo_mail_led_blink(struct led_classdev *led_cdev, > @@ -114,8 +109,6 @@ static int clevo_mail_led_blink(struct led_classdev *led_cdev, > { > int status = -EINVAL; > > - i8042_lock_chip(); > - > if (*delay_on == 0 /* ms */ && *delay_off == 0 /* ms */) { > /* Special case: the leds subsystem requested us to > * chose one user friendly blinking of the LED, and > @@ -142,8 +135,6 @@ static int clevo_mail_led_blink(struct led_classdev *led_cdev, > *delay_on, *delay_off); > } > > - i8042_unlock_chip(); > - > return status; > } > > diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c > index 60c18f21588dd..6cb6f800503b2 100644 > --- a/drivers/platform/x86/acer-wmi.c > +++ b/drivers/platform/x86/acer-wmi.c > @@ -1044,9 +1044,7 @@ static acpi_status WMID_set_u32(u32 value, u32 cap) > return AE_BAD_PARAMETER; > if (quirks->mailled == 1) { > param = value ? 0x92 : 0x93; > - i8042_lock_chip(); > i8042_command(¶m, 0x1059); > - i8042_unlock_chip(); > return 0; > } > break; > diff --git a/drivers/platform/x86/amilo-rfkill.c b/drivers/platform/x86/amilo-rfkill.c > index 493e169c8f615..c981c6e07ff94 100644 > --- a/drivers/platform/x86/amilo-rfkill.c > +++ b/drivers/platform/x86/amilo-rfkill.c > @@ -28,12 +28,8 @@ > static int amilo_a1655_rfkill_set_block(void *data, bool blocked) > { > u8 param = blocked ? A1655_WIFI_OFF : A1655_WIFI_ON; > - int rc; > > - i8042_lock_chip(); > - rc = i8042_command(¶m, A1655_WIFI_COMMAND); > - i8042_unlock_chip(); > - return rc; > + return i8042_command(¶m, A1655_WIFI_COMMAND); > } > > static const struct rfkill_ops amilo_a1655_rfkill_ops = { > diff --git a/include/linux/i8042.h b/include/linux/i8042.h > index 0261e2fb36364..1c081081c161d 100644 > --- a/include/linux/i8042.h > +++ b/include/linux/i8042.h > @@ -55,8 +55,6 @@ struct serio; > > #if defined(CONFIG_SERIO_I8042) || defined(CONFIG_SERIO_I8042_MODULE) > > -void i8042_lock_chip(void); > -void i8042_unlock_chip(void); > int i8042_command(unsigned char *param, int command); > int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str, > struct serio *serio)); > @@ -65,14 +63,6 @@ int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str, > > #else > > -static inline void i8042_lock_chip(void) > -{ > -} > - > -static inline void i8042_unlock_chip(void) > -{ > -} > - > static inline int i8042_command(unsigned char *param, int command) > { > return -ENODEV; >
Hi Raul, On Thu, Aug 27, 2020 at 02:41:53PM -0600, Raul E Rangel wrote: > The i8042_mutex must be held by writers of the AUX and KBD ports, as > well as users of i8042_command. There were a lot of users of > i8042_command that were not calling i8042_lock_chip/i8042_unlock_chip. > This resulted in i8042_commands being issues in between PS/2 > transactions. > > This change moves the mutex lock into i8042_command and removes the > burden of locking the mutex from the callers. I think there is a benefit for allowing users issue a sequence of commands to i8042 without interruptions, so I would prefer keeping i8042_[un]lock_chip() in place. Given that the issue you were observing was caused by i8042_port_close() interfering with probing, maybe we could do something like this: diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index abae23af0791..aff871001eda 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -344,6 +344,8 @@ int i8042_command(unsigned char *param, int command) unsigned long flags; int retval; + lockdep_assert_held(&i8042_mutex); + if (!i8042_present) return -1; @@ -364,6 +366,8 @@ static int i8042_kbd_write(struct serio *port, unsigned char c) unsigned long flags; int retval = 0; + lockdep_assert_held(&i8042_mutex); + spin_lock_irqsave(&i8042_lock, flags); if (!(retval = i8042_wait_write())) { @@ -411,6 +415,8 @@ static void i8042_port_close(struct serio *serio) port_name = "KBD"; } + i8042_lock_chip(); + i8042_ctr &= ~irq_bit; if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) pr_warn("Can't write CTR while closing %s port\n", port_name); @@ -422,6 +428,8 @@ static void i8042_port_close(struct serio *serio) if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR)) pr_err("Can't reactivate %s port\n", port_name); + i8042_unlock_chip(); + /* * See if there is any data appeared while we were messing with * port state. Thanks.
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index 0dddf273afd94..65ca6b47f41e8 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -137,8 +137,7 @@ static DEFINE_SPINLOCK(i8042_lock); /* * Writers to AUX and KBD ports as well as users issuing i8042_command - * directly should acquire i8042_mutex (by means of calling - * i8042_lock_chip() and i8042_unlock_ship() helpers) to ensure that + * directly should acquire i8042_mutex to ensure that * they do not disturb each other (unfortunately in many i8042 * implementations write to one of the ports will immediately abort * command that is being processed by another port). @@ -173,18 +172,6 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id); static bool (*i8042_platform_filter)(unsigned char data, unsigned char str, struct serio *serio); -void i8042_lock_chip(void) -{ - mutex_lock(&i8042_mutex); -} -EXPORT_SYMBOL(i8042_lock_chip); - -void i8042_unlock_chip(void) -{ - mutex_unlock(&i8042_mutex); -} -EXPORT_SYMBOL(i8042_unlock_chip); - int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str, struct serio *serio)) { @@ -343,10 +330,14 @@ int i8042_command(unsigned char *param, int command) unsigned long flags; int retval; + mutex_lock(&i8042_mutex); + spin_lock_irqsave(&i8042_lock, flags); retval = __i8042_command(param, command); spin_unlock_irqrestore(&i8042_lock, flags); + mutex_unlock(&i8042_mutex); + return retval; } EXPORT_SYMBOL(i8042_command); @@ -379,10 +370,18 @@ static int i8042_kbd_write(struct serio *port, unsigned char c) static int i8042_aux_write(struct serio *serio, unsigned char c) { struct i8042_port *port = serio->port_data; + unsigned long flags; + int retval = 0; + + spin_lock_irqsave(&i8042_lock, flags); - return i8042_command(&c, port->mux == -1 ? + retval = __i8042_command(&c, port->mux == -1 ? I8042_CMD_AUX_SEND : I8042_CMD_MUX_SEND + port->mux); + + spin_unlock_irqrestore(&i8042_lock, flags); + + return retval; } diff --git a/drivers/leds/leds-clevo-mail.c b/drivers/leds/leds-clevo-mail.c index f512e99b976b1..6c3d7e54f95cf 100644 --- a/drivers/leds/leds-clevo-mail.c +++ b/drivers/leds/leds-clevo-mail.c @@ -95,17 +95,12 @@ MODULE_DEVICE_TABLE(dmi, clevo_mail_led_dmi_table); static void clevo_mail_led_set(struct led_classdev *led_cdev, enum led_brightness value) { - i8042_lock_chip(); - if (value == LED_OFF) i8042_command(NULL, CLEVO_MAIL_LED_OFF); else if (value <= LED_HALF) i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ); else i8042_command(NULL, CLEVO_MAIL_LED_BLINK_1HZ); - - i8042_unlock_chip(); - } static int clevo_mail_led_blink(struct led_classdev *led_cdev, @@ -114,8 +109,6 @@ static int clevo_mail_led_blink(struct led_classdev *led_cdev, { int status = -EINVAL; - i8042_lock_chip(); - if (*delay_on == 0 /* ms */ && *delay_off == 0 /* ms */) { /* Special case: the leds subsystem requested us to * chose one user friendly blinking of the LED, and @@ -142,8 +135,6 @@ static int clevo_mail_led_blink(struct led_classdev *led_cdev, *delay_on, *delay_off); } - i8042_unlock_chip(); - return status; } diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c index 60c18f21588dd..6cb6f800503b2 100644 --- a/drivers/platform/x86/acer-wmi.c +++ b/drivers/platform/x86/acer-wmi.c @@ -1044,9 +1044,7 @@ static acpi_status WMID_set_u32(u32 value, u32 cap) return AE_BAD_PARAMETER; if (quirks->mailled == 1) { param = value ? 0x92 : 0x93; - i8042_lock_chip(); i8042_command(¶m, 0x1059); - i8042_unlock_chip(); return 0; } break; diff --git a/drivers/platform/x86/amilo-rfkill.c b/drivers/platform/x86/amilo-rfkill.c index 493e169c8f615..c981c6e07ff94 100644 --- a/drivers/platform/x86/amilo-rfkill.c +++ b/drivers/platform/x86/amilo-rfkill.c @@ -28,12 +28,8 @@ static int amilo_a1655_rfkill_set_block(void *data, bool blocked) { u8 param = blocked ? A1655_WIFI_OFF : A1655_WIFI_ON; - int rc; - i8042_lock_chip(); - rc = i8042_command(¶m, A1655_WIFI_COMMAND); - i8042_unlock_chip(); - return rc; + return i8042_command(¶m, A1655_WIFI_COMMAND); } static const struct rfkill_ops amilo_a1655_rfkill_ops = { diff --git a/include/linux/i8042.h b/include/linux/i8042.h index 0261e2fb36364..1c081081c161d 100644 --- a/include/linux/i8042.h +++ b/include/linux/i8042.h @@ -55,8 +55,6 @@ struct serio; #if defined(CONFIG_SERIO_I8042) || defined(CONFIG_SERIO_I8042_MODULE) -void i8042_lock_chip(void); -void i8042_unlock_chip(void); int i8042_command(unsigned char *param, int command); int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str, struct serio *serio)); @@ -65,14 +63,6 @@ int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str, #else -static inline void i8042_lock_chip(void) -{ -} - -static inline void i8042_unlock_chip(void) -{ -} - static inline int i8042_command(unsigned char *param, int command) { return -ENODEV;
The i8042_mutex must be held by writers of the AUX and KBD ports, as well as users of i8042_command. There were a lot of users of i8042_command that were not calling i8042_lock_chip/i8042_unlock_chip. This resulted in i8042_commands being issues in between PS/2 transactions. This change moves the mutex lock into i8042_command and removes the burden of locking the mutex from the callers. It is expected that the i8042_mutex is locked before calling i8042_aux_write or i8042_kbd_write. This is currently done by the PS/2 layer via ps2_begin_command and ps2_end_command. Other modules (serio_raw) do not currently lock the mutex, so there is still a possibility for intermixed commands. Link: https://lore.kernel.org/linux-input/CAHQZ30ANTeM-pgdYZ4AbgxsnevBJnJgKZ1Kg+Uy8oSXZUvz=og@mail.gmail.com Signed-off-by: Raul E Rangel <rrangel@chromium.org> --- Tested this on a device with only a PS/2 keyboard. I was able to do 1200+ suspend/resume cycles. Also tested this on a device with a PS/2 keyboard and a PS/2 mouse. I was able to do 250+ iterations with out problems. Changes in v2: - Fixed bad indent - Added Link: tag - Removed left over rc variable drivers/input/serio/i8042.c | 29 ++++++++++++++--------------- drivers/leds/leds-clevo-mail.c | 9 --------- drivers/platform/x86/acer-wmi.c | 2 -- drivers/platform/x86/amilo-rfkill.c | 6 +----- include/linux/i8042.h | 10 ---------- 5 files changed, 15 insertions(+), 41 deletions(-)