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.
>> > 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)