On 28/09/2021 04:40, Dmitry Baryshkov wrote:
On 28/09/2021 04:33, abhinavk@codeaurora.org wrote:
On 2021-09-27 18:29, Dmitry Baryshkov wrote:
On 28/09/2021 04:19, abhinavk@codeaurora.org wrote:
On 2021-09-27 18:06, Dmitry Baryshkov wrote:
On Tue, 28 Sept 2021 at 03:22, abhinavk@codeaurora.org wrote:
On 2021-09-25 12:43, Dmitry Baryshkov wrote: > On 21/09/2021 23:52, abhinavk@codeaurora.org wrote: >> On 2021-09-21 10:47, Dmitry Baryshkov wrote: >>> Hi, >>> >>> On Tue, 21 Sept 2021 at 20:01, abhinavk@codeaurora.org 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@linaro.org >>>> >>>> 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 >
Ah, I see your point. What about moving to msm_dsi_host_enable() then?
Yes, I had suggested this a few replies ago. But only at the dsi_msgr we know if DSI1 is also done. So you can do it right after it in below location?
427 if (is_dual_dsi && msm_dsi1) { 428 ret = msm_dsi_host_enable(msm_dsi1->host); 429 if (ret) { 430 pr_err("%s: enable host1 failed, %d\n", __func__, ret); 431 goto host1_en_fail; 432 } 433 }
<enable_irq here? >
If there is DSI1, it was also powered on/programmed at the time of msm_dsi_host_enable, so enabling IRQs from it should be safe. Do you see any pitfalls from enabling the irq from that function?
Just about symmetry. We will enable_irq() for DSI0 when DSI0 and DSI1 are powered on But for DSI1, we will enable it when its powered ON but not enabled. Hence i thought its better this way.
Ah. Then it would be better to call it between power_on() and enable(). I'll send v3.
V3 sent, moving the enable_irq() out of msm_dsi_host_power_on.
>>>> > 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)