From df5e4e8b576108f88f79e5b4c984d51d460d2360 Mon Sep 17 00:00:00 2001 From: Dasaratharaman Chandramouli Date: Tue, 10 Dec 2013 09:51:12 -0800 Subject: [PATCH] misc: mic: bug fix for interrupt acknowledgement in MSI/INTx case. The interrupt handler (mic_interrupt), called in the MSI/INTx mode, writes to the interrupt sources register to acknowledge the interrupt and then calls the corresponding callback handlers to handle the same. These callback handlers acknowledge the interrupts again leading to missed interrupts. This patch fixes the issue by removing the interrupt acknowlegment code from the callback handlers. Reviewed-by: Sudeep Dutt Reviewed-by: Nikhil Rao Reviewed-by: Siva Krishna Kumar Reddy Yerramreddy Signed-off-by: Dasaratharaman Chandramouli Cc: stable # 3.13 Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mic/host/mic_device.h | 3 +++ drivers/misc/mic/host/mic_main.c | 2 +- drivers/misc/mic/host/mic_virtio.c | 2 +- drivers/misc/mic/host/mic_x100.c | 36 +++++++++++++++++------------- 4 files changed, 25 insertions(+), 18 deletions(-) diff --git a/drivers/misc/mic/host/mic_device.h b/drivers/misc/mic/host/mic_device.h index 3574cc375bb9..b2da289320c9 100644 --- a/drivers/misc/mic/host/mic_device.h +++ b/drivers/misc/mic/host/mic_device.h @@ -134,6 +134,8 @@ struct mic_device { * @send_intr: Send an interrupt for a particular doorbell on the card. * @ack_interrupt: Hardware specific operations to ack the h/w on * receipt of an interrupt. + * @intr_workarounds: Hardware specific workarounds needed after + * handling an interrupt. * @reset: Reset the remote processor. * @reset_fw_ready: Reset firmware ready field. * @is_fw_ready: Check if firmware is ready for OS download. @@ -149,6 +151,7 @@ struct mic_hw_ops { void (*write_spad)(struct mic_device *mdev, unsigned int idx, u32 val); void (*send_intr)(struct mic_device *mdev, int doorbell); u32 (*ack_interrupt)(struct mic_device *mdev); + void (*intr_workarounds)(struct mic_device *mdev); void (*reset)(struct mic_device *mdev); void (*reset_fw_ready)(struct mic_device *mdev); bool (*is_fw_ready)(struct mic_device *mdev); diff --git a/drivers/misc/mic/host/mic_main.c b/drivers/misc/mic/host/mic_main.c index ad838c7651c4..c04a021e20c7 100644 --- a/drivers/misc/mic/host/mic_main.c +++ b/drivers/misc/mic/host/mic_main.c @@ -115,7 +115,7 @@ static irqreturn_t mic_shutdown_db(int irq, void *data) struct mic_device *mdev = data; struct mic_bootparam *bootparam = mdev->dp; - mdev->ops->ack_interrupt(mdev); + mdev->ops->intr_workarounds(mdev); switch (bootparam->shutdown_status) { case MIC_HALTED: diff --git a/drivers/misc/mic/host/mic_virtio.c b/drivers/misc/mic/host/mic_virtio.c index 5b8494bd1e00..8d3c21cd1d9c 100644 --- a/drivers/misc/mic/host/mic_virtio.c +++ b/drivers/misc/mic/host/mic_virtio.c @@ -369,7 +369,7 @@ static irqreturn_t mic_virtio_intr_handler(int irq, void *data) struct mic_vdev *mvdev = data; struct mic_device *mdev = mvdev->mdev; - mdev->ops->ack_interrupt(mdev); + mdev->ops->intr_workarounds(mdev); schedule_work(&mvdev->virtio_bh_work); return IRQ_HANDLED; } diff --git a/drivers/misc/mic/host/mic_x100.c b/drivers/misc/mic/host/mic_x100.c index 81e9541b784c..6fccb13493a5 100644 --- a/drivers/misc/mic/host/mic_x100.c +++ b/drivers/misc/mic/host/mic_x100.c @@ -174,35 +174,38 @@ static void mic_x100_send_intr(struct mic_device *mdev, int doorbell) } /** - * mic_ack_interrupt - Device specific interrupt handling. - * @mdev: pointer to mic_device instance + * mic_x100_ack_interrupt - Read the interrupt sources register and + * clear it. This function will be called in the MSI/INTx case. + * @mdev: Pointer to mic_device instance. * - * Returns: bitmask of doorbell events triggered. + * Returns: bitmask of interrupt sources triggered. */ static u32 mic_x100_ack_interrupt(struct mic_device *mdev) { - u32 reg = 0; - struct mic_mw *mw = &mdev->mmio; u32 sicr0 = MIC_X100_SBOX_BASE_ADDRESS + MIC_X100_SBOX_SICR0; + u32 reg = mic_mmio_read(&mdev->mmio, sicr0); + mic_mmio_write(&mdev->mmio, reg, sicr0); + return reg; +} + +/** + * mic_x100_intr_workarounds - These hardware specific workarounds are + * to be invoked everytime an interrupt is handled. + * @mdev: Pointer to mic_device instance. + * + * Returns: none + */ +static void mic_x100_intr_workarounds(struct mic_device *mdev) +{ + struct mic_mw *mw = &mdev->mmio; /* Clear pending bit array. */ if (MIC_A0_STEP == mdev->stepping) mic_mmio_write(mw, 1, MIC_X100_SBOX_BASE_ADDRESS + MIC_X100_SBOX_MSIXPBACR); - if (mdev->irq_info.num_vectors <= 1) { - reg = mic_mmio_read(mw, sicr0); - - if (unlikely(!reg)) - goto done; - - mic_mmio_write(mw, reg, sicr0); - } - if (mdev->stepping >= MIC_B0_STEP) mdev->intr_ops->enable_interrupts(mdev); -done: - return reg; } /** @@ -553,6 +556,7 @@ struct mic_hw_ops mic_x100_ops = { .write_spad = mic_x100_write_spad, .send_intr = mic_x100_send_intr, .ack_interrupt = mic_x100_ack_interrupt, + .intr_workarounds = mic_x100_intr_workarounds, .reset = mic_x100_hw_reset, .reset_fw_ready = mic_x100_reset_fw_ready, .is_fw_ready = mic_x100_is_fw_ready,