[PATCH 43/64] drm/vc4: hdmi: Protect device resources after removal
Thomas Zimmermann
tzimmermann at suse.de
Mon Jun 20 11:12:42 UTC 2022
Am 10.06.22 um 11:29 schrieb Maxime Ripard:
> Whenever the device and driver are unbound, the main device and all the
> subdevices will be removed by calling their unbind() method.
>
> However, the DRM device itself will only be freed when the last user will
> have closed it.
>
> It means that there is a time window where the device and its resources
> aren't there anymore, but the userspace can still call into our driver.
>
> Fortunately, the DRM framework provides the drm_dev_enter() and
> drm_dev_exit() functions to make sure our underlying device is still there
> for the section protected by those calls. Let's add them to the HDMI driver.
>
> Signed-off-by: Maxime Ripard <maxime at cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
> drivers/gpu/drm/vc4/vc4_hdmi.c | 286 +++++++++++++++++++++++++++++++--
> 1 file changed, 269 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 814517c1fdaa..b4fd581861ea 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -34,6 +34,7 @@
> #include <drm/display/drm_hdmi_helper.h>
> #include <drm/display/drm_scdc_helper.h>
> #include <drm/drm_atomic_helper.h>
> +#include <drm/drm_drv.h>
> #include <drm/drm_probe_helper.h>
> #include <drm/drm_simple_kms_helper.h>
> #include <linux/clk.h>
> @@ -140,17 +141,33 @@ static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused)
> {
> struct drm_info_node *node = (struct drm_info_node *)m->private;
> struct vc4_hdmi *vc4_hdmi = node->info_ent->data;
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> struct drm_printer p = drm_seq_file_printer(m);
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return -ENODEV;
>
> drm_print_regset32(&p, &vc4_hdmi->hdmi_regset);
> drm_print_regset32(&p, &vc4_hdmi->hd_regset);
>
> + drm_dev_exit(idx);
> +
> return 0;
> }
>
> static void vc4_hdmi_reset(struct vc4_hdmi *vc4_hdmi)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int idx;
> +
> + /*
> + * We can be called by our bind callback, when the
> + * connector->dev pointer might not be initialised yet.
> + */
> + if (drm && !drm_dev_enter(drm, &idx))
> + return;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -167,11 +184,23 @@ static void vc4_hdmi_reset(struct vc4_hdmi *vc4_hdmi)
> HDMI_WRITE(HDMI_SW_RESET_CONTROL, 0);
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + if (drm)
> + drm_dev_exit(idx);
> }
>
> static void vc5_hdmi_reset(struct vc4_hdmi *vc4_hdmi)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int idx;
> +
> + /*
> + * We can be called by our bind callback, when the
> + * connector->dev pointer might not be initialised yet.
> + */
> + if (drm && !drm_dev_enter(drm, &idx))
> + return;
>
> reset_control_reset(vc4_hdmi->reset);
>
> @@ -183,15 +212,25 @@ static void vc5_hdmi_reset(struct vc4_hdmi *vc4_hdmi)
> HDMI_READ(HDMI_CLOCK_STOP) | VC4_DVP_HT_CLOCK_STOP_PIXEL);
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + if (drm)
> + drm_dev_exit(idx);
> }
>
> #ifdef CONFIG_DRM_VC4_HDMI_CEC
> static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi)
> {
> - unsigned long cec_rate = clk_get_rate(vc4_hdmi->cec_clock);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> + unsigned long cec_rate;
> unsigned long flags;
> u16 clk_cnt;
> u32 value;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return;
> +
> + cec_rate = clk_get_rate(vc4_hdmi->cec_clock);
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -207,6 +246,8 @@ static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi)
> HDMI_WRITE(HDMI_CEC_CNTRL_1, value);
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + drm_dev_exit(idx);
> }
> #else
> static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi) {}
> @@ -427,25 +468,34 @@ static int vc4_hdmi_stop_packet(struct drm_encoder *encoder,
> bool poll)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> u32 packet_id = type - 0x80;
> unsigned long flags;
> + int ret = 0;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return -ENODEV;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
> HDMI_WRITE(HDMI_RAM_PACKET_CONFIG,
> HDMI_READ(HDMI_RAM_PACKET_CONFIG) & ~BIT(packet_id));
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
>
> - if (!poll)
> - return 0;
> + if (poll) {
> + ret = wait_for(!(HDMI_READ(HDMI_RAM_PACKET_STATUS) &
> + BIT(packet_id)), 100);
> + }
>
> - return wait_for(!(HDMI_READ(HDMI_RAM_PACKET_STATUS) &
> - BIT(packet_id)), 100);
> + drm_dev_exit(idx);
> + return ret;
> }
>
> static void vc4_hdmi_write_infoframe(struct drm_encoder *encoder,
> union hdmi_infoframe *frame)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> u32 packet_id = frame->any.type - 0x80;
> const struct vc4_hdmi_register *ram_packet_start =
> &vc4_hdmi->variant->registers[HDMI_RAM_PACKET_START];
> @@ -456,6 +506,10 @@ static void vc4_hdmi_write_infoframe(struct drm_encoder *encoder,
> unsigned long flags;
> ssize_t len, i;
> int ret;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return;
>
> WARN_ONCE(!(HDMI_READ(HDMI_RAM_PACKET_CONFIG) &
> VC4_HDMI_RAM_PACKET_ENABLE),
> @@ -463,12 +517,12 @@ static void vc4_hdmi_write_infoframe(struct drm_encoder *encoder,
>
> len = hdmi_infoframe_pack(frame, buffer, sizeof(buffer));
> if (len < 0)
> - return;
> + goto out;
>
> ret = vc4_hdmi_stop_packet(encoder, frame->any.type, true);
> if (ret) {
> DRM_ERROR("Failed to wait for infoframe to go idle: %d\n", ret);
> - return;
> + goto out;
> }
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
> @@ -497,6 +551,9 @@ static void vc4_hdmi_write_infoframe(struct drm_encoder *encoder,
> BIT(packet_id)), 100);
> if (ret)
> DRM_ERROR("Failed to wait for infoframe to start: %d\n", ret);
> +
> +out:
> + drm_dev_exit(idx);
> }
>
> static void vc4_hdmi_avi_infoframe_colorspace(struct hdmi_avi_infoframe *frame,
> @@ -644,8 +701,10 @@ static bool vc4_hdmi_supports_scrambling(struct drm_encoder *encoder,
> static void vc4_hdmi_enable_scrambling(struct drm_encoder *encoder)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
> unsigned long flags;
> + int idx;
>
> lockdep_assert_held(&vc4_hdmi->mutex);
>
> @@ -657,6 +716,9 @@ static void vc4_hdmi_enable_scrambling(struct drm_encoder *encoder)
> vc4_hdmi->output_format))
> return;
>
> + if (!drm_dev_enter(drm, &idx))
> + return;
> +
> drm_scdc_set_high_tmds_clock_ratio(vc4_hdmi->ddc, true);
> drm_scdc_set_scrambling(vc4_hdmi->ddc, true);
>
> @@ -665,6 +727,8 @@ static void vc4_hdmi_enable_scrambling(struct drm_encoder *encoder)
> VC5_HDMI_SCRAMBLER_CTL_ENABLE);
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
>
> + drm_dev_exit(idx);
> +
> vc4_hdmi->scdc_enabled = true;
>
> queue_delayed_work(system_wq, &vc4_hdmi->scrambling_work,
> @@ -674,7 +738,9 @@ static void vc4_hdmi_enable_scrambling(struct drm_encoder *encoder)
> static void vc4_hdmi_disable_scrambling(struct drm_encoder *encoder)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int idx;
>
> lockdep_assert_held(&vc4_hdmi->mutex);
>
> @@ -686,6 +752,9 @@ static void vc4_hdmi_disable_scrambling(struct drm_encoder *encoder)
> if (delayed_work_pending(&vc4_hdmi->scrambling_work))
> cancel_delayed_work_sync(&vc4_hdmi->scrambling_work);
>
> + if (!drm_dev_enter(drm, &idx))
> + return;
> +
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
> HDMI_WRITE(HDMI_SCRAMBLER_CTL, HDMI_READ(HDMI_SCRAMBLER_CTL) &
> ~VC5_HDMI_SCRAMBLER_CTL_ENABLE);
> @@ -693,6 +762,8 @@ static void vc4_hdmi_disable_scrambling(struct drm_encoder *encoder)
>
> drm_scdc_set_scrambling(vc4_hdmi->ddc, false);
> drm_scdc_set_high_tmds_clock_ratio(vc4_hdmi->ddc, false);
> +
> + drm_dev_exit(idx);
> }
>
> static void vc4_hdmi_scrambling_wq(struct work_struct *work)
> @@ -715,10 +786,15 @@ static void vc4_hdmi_encoder_post_crtc_disable(struct drm_encoder *encoder,
> struct drm_atomic_state *state)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int idx;
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx))
> + goto out;
> +
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> HDMI_WRITE(HDMI_RAM_PACKET_CONFIG, 0);
> @@ -736,6 +812,9 @@ static void vc4_hdmi_encoder_post_crtc_disable(struct drm_encoder *encoder,
>
> vc4_hdmi_disable_scrambling(encoder);
>
> + drm_dev_exit(idx);
> +
> +out:
> mutex_unlock(&vc4_hdmi->mutex);
> }
>
> @@ -743,11 +822,16 @@ static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder,
> struct drm_atomic_state *state)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> int ret;
> + int idx;
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx))
> + goto out;
> +
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
> HDMI_WRITE(HDMI_VID_CTL,
> HDMI_READ(HDMI_VID_CTL) | VC4_HD_VID_CTL_BLANKPIX);
> @@ -763,6 +847,9 @@ static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder,
> if (ret < 0)
> DRM_ERROR("Failed to release power domain: %d\n", ret);
>
> + drm_dev_exit(idx);
> +
> +out:
> mutex_unlock(&vc4_hdmi->mutex);
> }
>
> @@ -779,8 +866,13 @@ static void vc4_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
> struct drm_connector_state *state,
> const struct drm_display_mode *mode)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> u32 csc_ctl;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -815,6 +907,8 @@ static void vc4_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
> HDMI_WRITE(HDMI_CSC_CTL, csc_ctl);
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + drm_dev_exit(idx);
> }
>
> /*
> @@ -899,6 +993,7 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
> struct drm_connector_state *state,
> const struct drm_display_mode *mode)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> struct vc4_hdmi_connector_state *vc4_state =
> conn_state_to_vc4_hdmi_conn_state(state);
> unsigned long flags;
> @@ -907,6 +1002,10 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
> u32 csc_chan_ctl = 0;
> u32 csc_ctl = VC5_MT_CP_CSC_CTL_ENABLE | VC4_SET_FIELD(VC4_HD_CSC_CTL_MODE_CUSTOM,
> VC5_MT_CP_CSC_CTL_MODE);
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -949,12 +1048,15 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
> HDMI_WRITE(HDMI_CSC_CTL, csc_ctl);
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + drm_dev_exit(idx);
> }
>
> static void vc4_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
> struct drm_connector_state *state,
> struct drm_display_mode *mode)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> bool hsync_pos = mode->flags & DRM_MODE_FLAG_PHSYNC;
> bool vsync_pos = mode->flags & DRM_MODE_FLAG_PVSYNC;
> bool interlaced = mode->flags & DRM_MODE_FLAG_INTERLACE;
> @@ -973,6 +1075,10 @@ static void vc4_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
> interlaced,
> VC4_HDMI_VERTB_VBP));
> unsigned long flags;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -1000,12 +1106,15 @@ static void vc4_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
> HDMI_WRITE(HDMI_VERTB1, vertb);
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + drm_dev_exit(idx);
> }
>
> static void vc5_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
> struct drm_connector_state *state,
> struct drm_display_mode *mode)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> const struct vc4_hdmi_connector_state *vc4_state =
> conn_state_to_vc4_hdmi_conn_state(state);
> bool hsync_pos = mode->flags & DRM_MODE_FLAG_PHSYNC;
> @@ -1029,6 +1138,10 @@ static void vc5_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
> unsigned char gcp;
> bool gcp_en;
> u32 reg;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -1100,13 +1213,20 @@ static void vc5_hdmi_set_timings(struct vc4_hdmi *vc4_hdmi,
> HDMI_WRITE(HDMI_CLOCK_STOP, 0);
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + drm_dev_exit(idx);
> }
>
> static void vc4_hdmi_recenter_fifo(struct vc4_hdmi *vc4_hdmi)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> u32 drift;
> int ret;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -1135,12 +1255,15 @@ static void vc4_hdmi_recenter_fifo(struct vc4_hdmi *vc4_hdmi)
> VC4_HDMI_FIFO_CTL_RECENTER_DONE, 1);
> WARN_ONCE(ret, "Timeout waiting for "
> "VC4_HDMI_FIFO_CTL_RECENTER_DONE");
> +
> + drm_dev_exit(idx);
> }
>
> static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
> struct drm_atomic_state *state)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> struct drm_connector *connector = &vc4_hdmi->connector;
> struct drm_connector_state *conn_state =
> drm_atomic_get_new_connector_state(state, connector);
> @@ -1151,9 +1274,13 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
> unsigned long bvb_rate, hsm_rate;
> unsigned long flags;
> int ret;
> + int idx;
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx))
> + goto out;
> +
> /*
> * As stated in RPi's vc4 firmware "HDMI state machine (HSM) clock must
> * be faster than pixel clock, infinitesimally faster, tested in
> @@ -1174,13 +1301,13 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
> ret = clk_set_min_rate(vc4_hdmi->hsm_clock, hsm_rate);
> if (ret) {
> DRM_ERROR("Failed to set HSM clock rate: %d\n", ret);
> - goto out;
> + goto err_dev_exit;
> }
>
> ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
> if (ret < 0) {
> DRM_ERROR("Failed to retain power domain: %d\n", ret);
> - goto out;
> + goto err_dev_exit;
> }
>
> ret = clk_set_rate(vc4_hdmi->pixel_clock, tmds_char_rate);
> @@ -1232,6 +1359,8 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
> if (vc4_hdmi->variant->set_timings)
> vc4_hdmi->variant->set_timings(vc4_hdmi, conn_state, mode);
>
> + drm_dev_exit(idx);
> +
> mutex_unlock(&vc4_hdmi->mutex);
>
> return;
> @@ -1240,6 +1369,8 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
> clk_disable_unprepare(vc4_hdmi->pixel_clock);
> err_put_runtime_pm:
> pm_runtime_put(&vc4_hdmi->pdev->dev);
> +err_dev_exit:
> + drm_dev_exit(idx);
> out:
> mutex_unlock(&vc4_hdmi->mutex);
> return;
> @@ -1249,14 +1380,19 @@ static void vc4_hdmi_encoder_pre_crtc_enable(struct drm_encoder *encoder,
> struct drm_atomic_state *state)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> struct drm_connector *connector = &vc4_hdmi->connector;
> struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
> struct drm_connector_state *conn_state =
> drm_atomic_get_new_connector_state(state, connector);
> unsigned long flags;
> + int idx;
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx))
> + return;
> +
> if (vc4_hdmi->variant->csc_setup)
> vc4_hdmi->variant->csc_setup(vc4_hdmi, conn_state, mode);
>
> @@ -1264,6 +1400,8 @@ static void vc4_hdmi_encoder_pre_crtc_enable(struct drm_encoder *encoder,
> HDMI_WRITE(HDMI_FIFO_CTL, VC4_HDMI_FIFO_CTL_MASTER_SLAVE_N);
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
>
> + drm_dev_exit(idx);
> +
> mutex_unlock(&vc4_hdmi->mutex);
> }
>
> @@ -1271,15 +1409,20 @@ static void vc4_hdmi_encoder_post_crtc_enable(struct drm_encoder *encoder,
> struct drm_atomic_state *state)
> {
> struct vc4_hdmi *vc4_hdmi = encoder_to_vc4_hdmi(encoder);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> struct drm_display_mode *mode = &vc4_hdmi->saved_adjusted_mode;
> struct drm_display_info *display = &vc4_hdmi->connector.display_info;
> bool hsync_pos = mode->flags & DRM_MODE_FLAG_PHSYNC;
> bool vsync_pos = mode->flags & DRM_MODE_FLAG_PVSYNC;
> unsigned long flags;
> int ret;
> + int idx;
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx))
> + return;
> +
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> HDMI_WRITE(HDMI_VID_CTL,
> @@ -1340,6 +1483,7 @@ static void vc4_hdmi_encoder_post_crtc_enable(struct drm_encoder *encoder,
> vc4_hdmi_recenter_fifo(vc4_hdmi);
> vc4_hdmi_enable_scrambling(encoder);
>
> + drm_dev_exit(idx);
> mutex_unlock(&vc4_hdmi->mutex);
> }
>
> @@ -1675,13 +1819,20 @@ static u32 vc5_hdmi_channel_map(struct vc4_hdmi *vc4_hdmi, u32 channel_mask)
>
> static bool vc5_hdmi_hp_detect(struct vc4_hdmi *vc4_hdmi)
> {
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> u32 hotplug;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return false;
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
> hotplug = HDMI_READ(HDMI_HOTPLUG);
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
>
> + drm_dev_exit(idx);
> +
> return !!(hotplug & VC4_HDMI_HOTPLUG_CONNECTED);
> }
>
> @@ -1689,10 +1840,16 @@ static bool vc5_hdmi_hp_detect(struct vc4_hdmi *vc4_hdmi)
> static void vc4_hdmi_audio_set_mai_clock(struct vc4_hdmi *vc4_hdmi,
> unsigned int samplerate)
> {
> - u32 hsm_clock = clk_get_rate(vc4_hdmi->audio_clock);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> + u32 hsm_clock;
> unsigned long flags;
> unsigned long n, m;
> + int idx;
>
> + if (!drm_dev_enter(drm, &idx))
> + return;
> +
> + hsm_clock = clk_get_rate(vc4_hdmi->audio_clock);
> rational_best_approximation(hsm_clock, samplerate,
> VC4_HD_MAI_SMP_N_MASK >>
> VC4_HD_MAI_SMP_N_SHIFT,
> @@ -1705,6 +1862,8 @@ static void vc4_hdmi_audio_set_mai_clock(struct vc4_hdmi *vc4_hdmi,
> VC4_SET_FIELD(n, VC4_HD_MAI_SMP_N) |
> VC4_SET_FIELD(m - 1, VC4_HD_MAI_SMP_M));
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
> +
> + drm_dev_exit(idx);
> }
>
> static void vc4_hdmi_set_n_cts(struct vc4_hdmi *vc4_hdmi, unsigned int samplerate)
> @@ -1764,13 +1923,21 @@ static bool vc4_hdmi_audio_can_stream(struct vc4_hdmi *vc4_hdmi)
> static int vc4_hdmi_audio_startup(struct device *dev, void *data)
> {
> struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int ret = 0;
> + int idx;
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx)) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> if (!vc4_hdmi_audio_can_stream(vc4_hdmi)) {
> - mutex_unlock(&vc4_hdmi->mutex);
> - return -ENODEV;
> + ret = -ENODEV;
> + goto out_dev_exit;
> }
>
> vc4_hdmi->audio.streaming = true;
> @@ -1787,9 +1954,12 @@ static int vc4_hdmi_audio_startup(struct device *dev, void *data)
> if (vc4_hdmi->variant->phy_rng_enable)
> vc4_hdmi->variant->phy_rng_enable(vc4_hdmi);
>
> +out_dev_exit:
> + drm_dev_exit(idx);
> +out:
> mutex_unlock(&vc4_hdmi->mutex);
>
> - return 0;
> + return ret;
> }
>
> static void vc4_hdmi_audio_reset(struct vc4_hdmi *vc4_hdmi)
> @@ -1818,10 +1988,15 @@ static void vc4_hdmi_audio_reset(struct vc4_hdmi *vc4_hdmi)
> static void vc4_hdmi_audio_shutdown(struct device *dev, void *data)
> {
> struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int idx;
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx))
> + goto out;
> +
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> HDMI_WRITE(HDMI_MAI_CTL,
> @@ -1837,6 +2012,9 @@ static void vc4_hdmi_audio_shutdown(struct device *dev, void *data)
> vc4_hdmi->audio.streaming = false;
> vc4_hdmi_audio_reset(vc4_hdmi);
>
> + drm_dev_exit(idx);
> +
> +out:
> mutex_unlock(&vc4_hdmi->mutex);
> }
>
> @@ -1884,6 +2062,7 @@ static int vc4_hdmi_audio_prepare(struct device *dev, void *data,
> struct hdmi_codec_params *params)
> {
> struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> struct drm_encoder *encoder = &vc4_hdmi->encoder.base;
> unsigned int sample_rate = params->sample_rate;
> unsigned int channels = params->channels;
> @@ -1892,15 +2071,22 @@ static int vc4_hdmi_audio_prepare(struct device *dev, void *data,
> u32 channel_map;
> u32 mai_audio_format;
> u32 mai_sample_rate;
> + int ret = 0;
> + int idx;
>
> dev_dbg(dev, "%s: %u Hz, %d bit, %d channels\n", __func__,
> sample_rate, params->sample_width, channels);
>
> mutex_lock(&vc4_hdmi->mutex);
>
> + if (!drm_dev_enter(drm, &idx)) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> if (!vc4_hdmi_audio_can_stream(vc4_hdmi)) {
> - mutex_unlock(&vc4_hdmi->mutex);
> - return -EINVAL;
> + ret = -EINVAL;
> + goto out_dev_exit;
> }
>
> vc4_hdmi_audio_set_mai_clock(vc4_hdmi, sample_rate);
> @@ -1957,9 +2143,12 @@ static int vc4_hdmi_audio_prepare(struct device *dev, void *data,
> memcpy(&vc4_hdmi->audio.infoframe, ¶ms->cea, sizeof(params->cea));
> vc4_hdmi_set_audio_infoframe(encoder);
>
> +out_dev_exit:
> + drm_dev_exit(idx);
> +out:
> mutex_unlock(&vc4_hdmi->mutex);
>
> - return 0;
> + return ret;
> }
>
> static const struct snd_soc_component_driver vc4_hdmi_audio_cpu_dai_comp = {
> @@ -2294,6 +2483,17 @@ static irqreturn_t vc4_cec_irq_handler_tx_bare_locked(struct vc4_hdmi *vc4_hdmi)
> {
> u32 cntrl1;
>
> + /*
> + * We don't need to protect the register access using
> + * drm_dev_enter() there because the interrupt handler lifetime
> + * is tied to the device itself, and not to the DRM device.
> + *
> + * So when the device will be gone, one of the first thing we
> + * will be doing will be to unregister the interrupt handler,
> + * and then unregister the DRM device. drm_dev_enter() would
> + * thus always succeed if we are here.
> + */
> +
> lockdep_assert_held(&vc4_hdmi->hw_lock);
>
> cntrl1 = HDMI_READ(HDMI_CEC_CNTRL_1);
> @@ -2322,6 +2522,17 @@ static irqreturn_t vc4_cec_irq_handler_rx_bare_locked(struct vc4_hdmi *vc4_hdmi)
>
> lockdep_assert_held(&vc4_hdmi->hw_lock);
>
> + /*
> + * We don't need to protect the register access using
> + * drm_dev_enter() there because the interrupt handler lifetime
> + * is tied to the device itself, and not to the DRM device.
> + *
> + * So when the device will be gone, one of the first thing we
> + * will be doing will be to unregister the interrupt handler,
> + * and then unregister the DRM device. drm_dev_enter() would
> + * thus always succeed if we are here.
> + */
> +
> vc4_hdmi->cec_rx_msg.len = 0;
> cntrl1 = HDMI_READ(HDMI_CEC_CNTRL_1);
> vc4_cec_read_msg(vc4_hdmi, cntrl1);
> @@ -2353,6 +2564,17 @@ static irqreturn_t vc4_cec_irq_handler(int irq, void *priv)
> irqreturn_t ret;
> u32 cntrl5;
>
> + /*
> + * We don't need to protect the register access using
> + * drm_dev_enter() there because the interrupt handler lifetime
> + * is tied to the device itself, and not to the DRM device.
> + *
> + * So when the device will be gone, one of the first thing we
> + * will be doing will be to unregister the interrupt handler,
> + * and then unregister the DRM device. drm_dev_enter() would
> + * thus always succeed if we are here.
> + */
> +
> if (!(stat & VC4_HDMI_CPU_CEC))
> return IRQ_NONE;
>
> @@ -2373,11 +2595,13 @@ static irqreturn_t vc4_cec_irq_handler(int irq, void *priv)
> static int vc4_hdmi_cec_enable(struct cec_adapter *adap)
> {
> struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> /* clock period in microseconds */
> const u32 usecs = 1000000 / CEC_CLOCK_FREQ;
> unsigned long flags;
> u32 val;
> int ret;
> + int idx;
>
> /*
> * NOTE: This function should really take vc4_hdmi->mutex, but doing so
> @@ -2390,9 +2614,14 @@ static int vc4_hdmi_cec_enable(struct cec_adapter *adap)
> * keep it in mind if we were to change that assumption.
> */
>
> + if (!drm_dev_enter(drm, &idx))
> + return -ENODEV;
> +
> ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
> - if (ret)
> + if (ret) {
> + drm_dev_exit(idx);
> return ret;
> + }
>
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
>
> @@ -2428,13 +2657,20 @@ static int vc4_hdmi_cec_enable(struct cec_adapter *adap)
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
>
> + drm_dev_exit(idx);
> +
> return 0;
> }
>
> static int vc4_hdmi_cec_disable(struct cec_adapter *adap)
> {
> struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int idx;
> +
> + if (!drm_dev_enter(drm, &idx))
> + return -ENODEV;
>
> /*
> * NOTE: This function should really take vc4_hdmi->mutex, but doing so
> @@ -2459,6 +2695,8 @@ static int vc4_hdmi_cec_disable(struct cec_adapter *adap)
>
> pm_runtime_put(&vc4_hdmi->pdev->dev);
>
> + drm_dev_exit(idx);
> +
> return 0;
> }
>
> @@ -2473,7 +2711,9 @@ static int vc4_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
> static int vc4_hdmi_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
> {
> struct vc4_hdmi *vc4_hdmi = cec_get_drvdata(adap);
> + struct drm_device *drm = vc4_hdmi->connector.dev;
> unsigned long flags;
> + int idx;
>
> /*
> * NOTE: This function should really take vc4_hdmi->mutex, but doing so
> @@ -2486,12 +2726,17 @@ static int vc4_hdmi_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
> * keep it in mind if we were to change that assumption.
> */
>
> + if (!drm_dev_enter(drm, &idx))
> + return -ENODEV;
> +
> spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
> HDMI_WRITE(HDMI_CEC_CNTRL_1,
> (HDMI_READ(HDMI_CEC_CNTRL_1) & ~VC4_HDMI_CEC_ADDR_MASK) |
> (log_addr & 0xf) << VC4_HDMI_CEC_ADDR_SHIFT);
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
>
> + drm_dev_exit(idx);
> +
> return 0;
> }
>
> @@ -2503,6 +2748,7 @@ static int vc4_hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
> unsigned long flags;
> u32 val;
> unsigned int i;
> + int idx;
>
> /*
> * NOTE: This function should really take vc4_hdmi->mutex, but doing so
> @@ -2515,8 +2761,12 @@ static int vc4_hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
> * keep it in mind if we were to change that assumption.
> */
>
> + if (!drm_dev_enter(dev, &idx))
> + return -ENODEV;
> +
> if (msg->len > 16) {
> drm_err(dev, "Attempting to transmit too much data (%d)\n", msg->len);
> + drm_dev_exit(idx);
> return -ENOMEM;
> }
>
> @@ -2540,6 +2790,8 @@ static int vc4_hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
>
> spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
>
> + drm_dev_exit(idx);
> +
> return 0;
> }
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev
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