diff options
author | Tomas Winkler <tomas.winkler@intel.com> | 2022-09-08 00:51:03 +0300 |
---|---|---|
committer | Joonas Lahtinen <joonas.lahtinen@linux.intel.com> | 2022-09-12 15:23:10 +0300 |
commit | 5b063995de950d45edecf25a3eac5d8a44bd0ab9 (patch) | |
tree | 74418db65cecde6d14b038c97d4f33d450678843 /drivers/misc/mei/hw-me.c | |
parent | 2d427248aac4e4c8daeb1a4e021f9e22eb0c8e6f (diff) | |
download | linux-5b063995de950d45edecf25a3eac5d8a44bd0ab9.tar.xz |
mei: gsc: use polling instead of interrupts
A work-around for a HW issue in XEHPSDV that manifests itself when SW reads
a gsc register when gsc is sending an interrupt. The work-around is
to disable interrupts and to use polling instead.
Cc: James Ausmus <james.ausmus@intel.com>
Signed-off-by: Vitaly Lubart <vitaly.lubart@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220907215113.1596567-7-tomas.winkler@intel.com
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers/misc/mei/hw-me.c')
-rw-r--r-- | drivers/misc/mei/hw-me.c | 80 |
1 files changed, 75 insertions, 5 deletions
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c index 9870bf717979..1703e197ba62 100644 --- a/drivers/misc/mei/hw-me.c +++ b/drivers/misc/mei/hw-me.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 /* - * Copyright (c) 2003-2020, Intel Corporation. All rights reserved. + * Copyright (c) 2003-2022, Intel Corporation. All rights reserved. * Intel Management Engine Interface (Intel MEI) Linux driver */ @@ -10,6 +10,7 @@ #include <linux/interrupt.h> #include <linux/pm_runtime.h> #include <linux/sizes.h> +#include <linux/delay.h> #include "mei_dev.h" #include "hbm.h" @@ -327,9 +328,12 @@ static void mei_me_intr_clear(struct mei_device *dev) */ static void mei_me_intr_enable(struct mei_device *dev) { - u32 hcsr = mei_hcsr_read(dev); + u32 hcsr; + + if (mei_me_hw_use_polling(to_me_hw(dev))) + return; - hcsr |= H_CSR_IE_MASK; + hcsr = mei_hcsr_read(dev) | H_CSR_IE_MASK; mei_hcsr_set(dev, hcsr); } @@ -354,6 +358,9 @@ static void mei_me_synchronize_irq(struct mei_device *dev) { struct mei_me_hw *hw = to_me_hw(dev); + if (mei_me_hw_use_polling(hw)) + return; + synchronize_irq(hw->irq); } @@ -380,7 +387,10 @@ static void mei_me_host_set_ready(struct mei_device *dev) { u32 hcsr = mei_hcsr_read(dev); - hcsr |= H_CSR_IE_MASK | H_IG | H_RDY; + if (!mei_me_hw_use_polling(to_me_hw(dev))) + hcsr |= H_CSR_IE_MASK; + + hcsr |= H_IG | H_RDY; mei_hcsr_set(dev, hcsr); } @@ -1174,7 +1184,7 @@ static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable) hcsr |= H_RST | H_IG | H_CSR_IS_MASK; - if (!intr_enable) + if (!intr_enable || mei_me_hw_use_polling(to_me_hw(dev))) hcsr &= ~H_CSR_IE_MASK; dev->recvd_hw_ready = false; @@ -1329,6 +1339,66 @@ end: } EXPORT_SYMBOL_GPL(mei_me_irq_thread_handler); +#define MEI_POLLING_TIMEOUT_ACTIVE 100 +#define MEI_POLLING_TIMEOUT_IDLE 500 + +/** + * mei_me_polling_thread - interrupt register polling thread + * + * The thread monitors the interrupt source register and calls + * mei_me_irq_thread_handler() to handle the firmware + * input. + * + * The function polls in MEI_POLLING_TIMEOUT_ACTIVE timeout + * in case there was an event, in idle case the polling + * time increases yet again by MEI_POLLING_TIMEOUT_ACTIVE + * up to MEI_POLLING_TIMEOUT_IDLE. + * + * @_dev: mei device + * + * Return: always 0 + */ +int mei_me_polling_thread(void *_dev) +{ + struct mei_device *dev = _dev; + irqreturn_t irq_ret; + long polling_timeout = MEI_POLLING_TIMEOUT_ACTIVE; + + dev_dbg(dev->dev, "kernel thread is running\n"); + while (!kthread_should_stop()) { + struct mei_me_hw *hw = to_me_hw(dev); + u32 hcsr; + + wait_event_timeout(hw->wait_active, + hw->is_active || kthread_should_stop(), + msecs_to_jiffies(MEI_POLLING_TIMEOUT_IDLE)); + + if (kthread_should_stop()) + break; + + hcsr = mei_hcsr_read(dev); + if (me_intr_src(hcsr)) { + polling_timeout = MEI_POLLING_TIMEOUT_ACTIVE; + irq_ret = mei_me_irq_thread_handler(1, dev); + if (irq_ret != IRQ_HANDLED) + dev_err(dev->dev, "irq_ret %d\n", irq_ret); + } else { + /* + * Increase timeout by MEI_POLLING_TIMEOUT_ACTIVE + * up to MEI_POLLING_TIMEOUT_IDLE + */ + polling_timeout = clamp_val(polling_timeout + MEI_POLLING_TIMEOUT_ACTIVE, + MEI_POLLING_TIMEOUT_ACTIVE, + MEI_POLLING_TIMEOUT_IDLE); + } + + schedule_timeout_interruptible(msecs_to_jiffies(polling_timeout)); + } + + return 0; +} +EXPORT_SYMBOL_GPL(mei_me_polling_thread); + static const struct mei_hw_ops mei_me_hw_ops = { .trc_status = mei_me_trc_status, |