On 2021-09-25 12:43, Dmitry Baryshkov wrote:
On 21/09/2021 23:52, abhinavk@xxxxxxxxxxxxxx wrote:
On 2021-09-21 10:47, Dmitry Baryshkov wrote:
Hi,
On Tue, 21 Sept 2021 at 20:01, <abhinavk@xxxxxxxxxxxxxx> wrote:
On 2021-09-21 09:22, Dmitry Baryshkov wrote:
> The DSI host might be left in some state by the bootloader. If this
> state generates an IRQ, it might hang the system by holding the
> interrupt line before the driver sets up the DSI host to the known
> state.
>
> Move the request/free_irq calls into msm_dsi_host_power_on/_off calls,
> so that we can be sure that the interrupt is delivered when the host is
> in the known state.
>
> Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
This is a valid change and we have seen interrupt storms in
downstream
happening
when like you said the bootloader leaves the DSI host in unknown
state.
Just one question below.
> ---
> drivers/gpu/drm/msm/dsi/dsi_host.c | 21 ++++++++++++---------
> 1 file changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c
> b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index e269df285136..cd842347a6b1 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -1951,15 +1951,6 @@ int msm_dsi_host_modeset_init(struct
> mipi_dsi_host *host,
> return ret;
> }
>
> - ret = devm_request_irq(&pdev->dev, msm_host->irq,
> - dsi_host_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> - "dsi_isr", msm_host);
> - if (ret < 0) {
> - DRM_DEV_ERROR(&pdev->dev, "failed to request IRQ%u: %d\n",
> - msm_host->irq, ret);
> - return ret;
> - }
> -
> msm_host->dev = dev;
> ret = cfg_hnd->ops->tx_buf_alloc(msm_host, SZ_4K);
> if (ret) {
> @@ -2413,6 +2404,16 @@ int msm_dsi_host_power_on(struct mipi_dsi_host
> *host,
> if (msm_host->disp_en_gpio)
> gpiod_set_value(msm_host->disp_en_gpio, 1);
>
> + ret = devm_request_irq(&msm_host->pdev->dev, msm_host->irq,
> + dsi_host_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> + "dsi_isr", msm_host);
> + if (ret < 0) {
> + DRM_DEV_ERROR(&msm_host->pdev->dev, "failed to request IRQ%u: %d\n",
> + msm_host->irq, ret);
> + return ret;
> + }
> +
> +
Do you want to move this to msm_dsi_host_enable()?
So without the controller being enabled it is still in unknown
state?
msm_dsi_host_power_on() reconfigures the host registers, so the state
is known at the end of the power_on().
Also do you want to do this after dsi0 and dsi1 are initialized to
account for
dual dsi cases?
I don't think this should matter. The host won't generate 'extra'
interrupts in such case, will it?
We have seen cases where misconfiguration has caused interrupts to
storm only
on one DSI in some cases. So yes, I would prefer this is done after
both are
configured.
I've checked. The power_on is called from dsi_mgr_bridge_pre_enable()
when both DSI hosts should be bound.
DSI being bound is enough? I thought the issue we are trying to address
is that
we need to have called msm_dsi_host_power_on() for both the hosts so
that both are
put in the known state before requesting the irq.
OR in other words move the irq_enable() to below location.
341 static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
342 {
********************************
364 ret = msm_dsi_host_power_on(host, &phy_shared_timings[id],
is_bonded_dsi, msm_dsi->phy);
365 if (ret) {
366 pr_err("%s: power on host %d failed, %d\n", __func__, id, ret);
367 goto host_on_fail;
368 }
369
370 if (is_bonded_dsi && msm_dsi1) {
371 ret = msm_dsi_host_power_on(msm_dsi1->host,
372 &phy_shared_timings[DSI_1], is_bonded_dsi, msm_dsi1->phy);
373 if (ret) {
374 pr_err("%s: power on host1 failed, %d\n",
375 __func__, ret);
376 goto host1_on_fail;
377 }
378 }
< move the irq enable here >
**********************************
> msm_host->power_on = true;
> mutex_unlock(&msm_host->dev_mutex);
>
> @@ -2439,6 +2440,8 @@ int msm_dsi_host_power_off(struct mipi_dsi_host
> *host)
> goto unlock_ret;
> }
>
> + devm_free_irq(&msm_host->pdev->dev, msm_host->irq, msm_host);
> +
> dsi_ctrl_config(msm_host, false, NULL, NULL);
>
> if (msm_host->disp_en_gpio)
