On Tue, Feb 11, 2025 at 7:27 PM Binbin Zhou <zhoubb.aa...@gmail.com> wrote: > > Hi Thomas: > > Sorry for my late reply and thanks for your advice. > > On Wed, Jan 15, 2025 at 2:57 PM Thomas Zimmermann <tzimmerm...@suse.de> wrote: > > > > Hi > > > > > > Am 30.12.24 um 10:31 schrieb Binbin Zhou: > > > Since the display is a sub-function of the Loongson-2K BMC, when the > > > BMC reset, the entire BMC PCIe is disconnected, including the display > > > which is interrupted. > > > > To me, that's a strong indicator to set up the entire thing from scratch. > > > > > > > > Not only do you need to save/restore the relevant PCIe registers > > > throughout the reset process, but you also need to re-push the display > > > to the monitor at the end. > > > > > > Co-developed-by: Chong Qiao <qiaoch...@loongson.cn> > > > Signed-off-by: Chong Qiao <qiaoch...@loongson.cn> > > > Signed-off-by: Binbin Zhou <zhoubin...@loongson.cn> > > > --- > > > drivers/gpu/drm/tiny/ls2kbmc.c | 284 ++++++++++++++++++++++++++++++++- > > > 1 file changed, 283 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/gpu/drm/tiny/ls2kbmc.c > > > b/drivers/gpu/drm/tiny/ls2kbmc.c > > > index 909d6c687193..4b440f20cb4d 100644 > > > --- a/drivers/gpu/drm/tiny/ls2kbmc.c > > > +++ b/drivers/gpu/drm/tiny/ls2kbmc.c > > > > Move all the reset detection into the BMC core driver. When you see a > > reset, remove the display's platform device via > > platform_device_unregister(). This will release the device and the DRM > > driver on top. We do this for simpledrm/efifb/etc. Hence user-space code > > is able to deal with it. Then set up a new platform device when the new > > framebuffer is available. Your DRM driver will bind to it and user-space > > code will continue with the new DRM device. > > I tried to refactor the bmc restart part according to your scheme. I'm > not quite sure if the experimental results are exactly right. > > Key part: > > New solution: > 1. platform_device_unregister(simpledrm) > 2. wait and detect if the BMC reboot is complete; > 3. platform_device_register_resndata(simpledrm) > > Original solution: > 1. wait and detect if the BMC reboot is complete; > 2. ls2kbmc_push_drm_mode() pushes display data such as crtc. > > When the BMC reboot is completed, the display in the new solution will > lose all the information of the previous desktop and redisplay the > system login interface, while the original solution will keep the > desktop information. > > Is this normal for our new solution, or is there something wrong with > my implementation?
Hi Thomas: Sorry to bother you and my last email[1] may have been lost. Some time ago, I modified the code and tested it based on your previous comments, but the results were a bit different than expected. I'm not sure if the code changes are wrong, so it would be great if you could take the time to help me out: [1]: https://lore.kernel.org/all/CAMpQs4JXKu4GDD79Mdkq9vASSDE_5SQsjsg4htfaZ5yGm3=k...@mail.gmail.com/ > > > > > Best regards > > Thomas > > > > > @@ -8,10 +8,12 @@ > > > */ > > > > > > #include <linux/aperture.h> > > > +#include <linux/delay.h> > > > #include <linux/minmax.h> > > > #include <linux/pci.h> > > > #include <linux/platform_data/simplefb.h> > > > #include <linux/platform_device.h> > > > +#include <linux/stop_machine.h> > > > > > > #include <drm/drm_atomic.h> > > > #include <drm/drm_atomic_state_helper.h> > > > @@ -32,9 +34,27 @@ > > > #include <drm/drm_panic.h> > > > #include <drm/drm_probe_helper.h> > > > > > > +#define BMC_RESET_DELAY (60 * HZ) > > > +#define BMC_RESET_WAIT 10000 > > > + > > > +static const u32 index[] = { 0x4, 0x10, 0x14, 0x18, 0x1c, 0x20, 0x24, > > > + 0x30, 0x3c, 0x54, 0x58, 0x78, 0x7c, 0x80 }; > > > +static const u32 cindex[] = { 0x4, 0x10, 0x3c }; > > > + > > > +struct ls2kbmc_pci_data { > > > + u32 d80c; > > > + u32 d71c; > > > + u32 data[14]; > > > + u32 cdata[3]; > > > +}; > > > + > > > struct ls2kbmc_pdata { > > > struct pci_dev *pdev; > > > + struct drm_device *ddev; > > > + struct work_struct bmc_work; > > > + unsigned long reset_time; > > > struct simplefb_platform_data pd; > > > + struct ls2kbmc_pci_data pci_data; > > > }; > > > > > > /* > > > @@ -583,6 +603,265 @@ static struct ls2kbmc_device > > > *ls2kbmc_device_create(struct drm_driver *drv, > > > return sdev; > > > } > > > > > > +static bool ls2kbmc_bar0_addr_is_set(struct pci_dev *ppdev) > > > +{ > > > + u32 addr; > > > + > > > + pci_read_config_dword(ppdev, PCI_BASE_ADDRESS_0, &addr); > > > + addr &= PCI_BASE_ADDRESS_MEM_MASK; > > > + > > > + return addr ? true : false; > > > +} > > > + > > > +static void ls2kbmc_save_pci_data(struct ls2kbmc_pdata *priv) > > > +{ > > > + struct pci_dev *pdev = priv->pdev; > > > + struct pci_dev *parent = pdev->bus->self; > > > + int i; > > > + > > > + for (i = 0; i < ARRAY_SIZE(index); i++) > > > + pci_read_config_dword(parent, index[i], > > > &priv->pci_data.data[i]); > > > + > > > + for (i = 0; i < ARRAY_SIZE(cindex); i++) > > > + pci_read_config_dword(pdev, cindex[i], > > > &priv->pci_data.cdata[i]); > > > + > > > + pci_read_config_dword(parent, 0x80c, &priv->pci_data.d80c); > > > + priv->pci_data.d80c = (priv->pci_data.d80c & ~(3 << 17)) | (1 << > > > 17); > > > + > > > + pci_read_config_dword(parent, 0x71c, &priv->pci_data.d71c); > > > + priv->pci_data.d71c |= 1 << 26; > > > +} > > > + > > > +static bool ls2kbmc_check_pcie_connected(struct pci_dev *parent, struct > > > drm_device *dev) > > > +{ > > > + void __iomem *mmio; > > > + int sts, timeout = 10000; > > > + > > > + mmio = pci_iomap(parent, 0, 0x100); > > > + if (!mmio) > > > + return false; > > > + > > > + writel(readl(mmio) | 0x8, mmio); > > > + while (timeout) { > > > + sts = readl(mmio + 0xc); > > > + if ((sts & 0x11) == 0x11) > > > + break; > > > + mdelay(1); > > > + timeout--; > > > + } > > > + > > > + pci_iounmap(parent, mmio); > > > + > > > + if (!timeout) { > > > + drm_err(dev, "pcie train failed status=0x%x\n", sts); > > > + return false; > > > + } > > > + > > > + return true; > > > +} > > > + > > > +static int ls2kbmc_recove_pci_data(void *data) > > > +{ > > > + struct ls2kbmc_pdata *priv = data; > > > + struct pci_dev *pdev = priv->pdev; > > > + struct drm_device *dev = priv->ddev; > > > + struct pci_dev *parent = pdev->bus->self; > > > + u32 i, timeout, retry = 0; > > > + bool ready; > > > + > > > + pci_write_config_dword(parent, PCI_BASE_ADDRESS_2, 0); > > > + pci_write_config_dword(parent, PCI_BASE_ADDRESS_3, 0); > > > + pci_write_config_dword(parent, PCI_BASE_ADDRESS_4, 0); > > > + > > > + timeout = 10000; > > > + while (timeout) { > > > + ready = ls2kbmc_bar0_addr_is_set(parent); > > > + if (!ready) > > > + break; > > > + mdelay(1); > > > + timeout--; > > > + }; > > > + > > > + if (!timeout) > > > + drm_warn(dev, "bar not clear 0\n"); > > > + > > > +retrain: > > > + for (i = 0; i < ARRAY_SIZE(index); i++) > > > + pci_write_config_dword(parent, index[i], > > > priv->pci_data.data[i]); > > > + > > > + pci_write_config_dword(parent, 0x80c, priv->pci_data.d80c); > > > + pci_write_config_dword(parent, 0x71c, priv->pci_data.d71c); > > > + > > > + /* Check if the pcie is connected */ > > > + ready = ls2kbmc_check_pcie_connected(parent, dev); > > > + if (!ready) > > > + return ready; > > > + > > > + for (i = 0; i < ARRAY_SIZE(cindex); i++) > > > + pci_write_config_dword(pdev, cindex[i], > > > priv->pci_data.cdata[i]); > > > + > > > + drm_info(dev, "pcie recovered done\n"); > > > + > > > + if (!retry) { > > > + /*wait u-boot ddr config */ > > > + mdelay(BMC_RESET_WAIT); > > > + ready = ls2kbmc_bar0_addr_is_set(parent); > > > + if (!ready) { > > > + retry = 1; > > > + goto retrain; > > > + } > > > + } > > > + > > > + return 0; > > > +} > > > + > > > +static int ls2kbmc_push_drm_mode(struct drm_device *dev) > > > +{ > > > + struct ls2kbmc_device *sdev = ls2kbmc_device_of_dev(dev); > > > + struct drm_crtc *crtc = &sdev->crtc; > > > + struct drm_plane *plane = crtc->primary; > > > + struct drm_connector *connector = &sdev->connector; > > > + struct drm_framebuffer *fb = NULL; > > > + struct drm_mode_set set; > > > + struct drm_modeset_acquire_ctx ctx; > > > + int ret; > > > + > > > + mutex_lock(&dev->mode_config.mutex); > > > + connector->funcs->fill_modes(connector, 4096, 4096); > > > + mutex_unlock(&dev->mode_config.mutex); > > > + > > > + DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, > > > + DRM_MODESET_ACQUIRE_INTERRUPTIBLE, ret); > > > + > > > + if (plane->state) > > > + fb = plane->state->fb; > > > + else > > > + fb = plane->fb; > > > + > > > + if (!fb) { > > > + drm_dbg(dev, "CRTC doesn't have current FB\n"); > > > + ret = -EINVAL; > > > + goto out; > > > + } > > > + > > > + drm_framebuffer_get(fb); > > > + > > > + set.crtc = crtc; > > > + set.x = 0; > > > + set.y = 0; > > > + set.mode = &sdev->mode; > > > + set.connectors = &connector; > > > + set.num_connectors = 1; > > > + set.fb = fb; > > > + > > > + ret = crtc->funcs->set_config(&set, &ctx); > > > + > > > +out: > > > + DRM_MODESET_LOCK_ALL_END(dev, ctx, ret); > > > + > > > + return ret; > > > +} > > > + > > > +static void ls2kbmc_events_fn(struct work_struct *work) > > > +{ > > > + struct ls2kbmc_pdata *priv = container_of(work, struct > > > ls2kbmc_pdata, bmc_work); > > > + > > > + /* > > > + * The pcie is lost when the BMC resets, > > > + * at which point access to the pcie from other CPUs > > > + * is suspended to prevent a crash. > > > + */ > > > + stop_machine(ls2kbmc_recove_pci_data, priv, NULL); > > > + > > > + drm_info(priv->ddev, "redraw console\n"); > > > + > > > + /* We need to re-push the display due to previous pcie loss. */ > > > + ls2kbmc_push_drm_mode(priv->ddev); > > > +} > > > + > > > +static irqreturn_t ls2kbmc_interrupt(int irq, void *arg) > > > +{ > > > + struct ls2kbmc_pdata *priv = arg; > > > + > > > + if (system_state != SYSTEM_RUNNING) > > > + return IRQ_HANDLED; > > > + > > > + /* skip interrupt in BMC_RESET_DELAY */ > > > + if (time_after(jiffies, priv->reset_time + BMC_RESET_DELAY)) > > > + schedule_work(&priv->bmc_work); > > > + > > > + priv->reset_time = jiffies; > > > + > > > + return IRQ_HANDLED; > > > +} > > > + > > > +#define BMC_RESET_GPIO 14 > > > +#define LOONGSON_GPIO_REG_BASE 0x1fe00500 > > > +#define LOONGSON_GPIO_REG_SIZE 0x18 > > > +#define LOONGSON_GPIO_OEN 0x0 > > > +#define LOONGSON_GPIO_FUNC 0x4 > > > +#define LOONGSON_GPIO_INTPOL 0x10 > > > +#define LOONGSON_GPIO_INTEN 0x14 > > > + > > > +/* The gpio interrupt is a watchdog interrupt that is triggered when the > > > BMC resets. */ > > > +static int ls2kbmc_gpio_reset_handler(struct ls2kbmc_pdata *priv) > > > +{ > > > + int irq, ret = 0; > > > + int gsi = 16 + (BMC_RESET_GPIO & 7); > > > + void __iomem *gpio_base; > > > + > > > + /* Since Loongson-3A hardware does not support GPIO interrupt > > > cascade, > > > + * chip->gpio_to_irq() cannot be implemented, > > > + * here acpi_register_gsi() is used to get gpio irq. > > > + */ > > > + irq = acpi_register_gsi(NULL, gsi, ACPI_EDGE_SENSITIVE, > > > ACPI_ACTIVE_LOW); > > > + if (irq < 0) > > > + return irq; > > > + > > > + gpio_base = ioremap(LOONGSON_GPIO_REG_BASE, LOONGSON_GPIO_REG_SIZE); > > > + if (!gpio_base) { > > > + acpi_unregister_gsi(gsi); > > > + return PTR_ERR(gpio_base); > > > + } > > > + > > > + writel(readl(gpio_base + LOONGSON_GPIO_OEN) | BIT(BMC_RESET_GPIO), > > > + gpio_base + LOONGSON_GPIO_OEN); > > > + writel(readl(gpio_base + LOONGSON_GPIO_FUNC) & ~BIT(BMC_RESET_GPIO), > > > + gpio_base + LOONGSON_GPIO_FUNC); > > > + writel(readl(gpio_base + LOONGSON_GPIO_INTPOL) & > > > ~BIT(BMC_RESET_GPIO), > > > + gpio_base + LOONGSON_GPIO_INTPOL); > > > + writel(readl(gpio_base + LOONGSON_GPIO_INTEN) | BIT(BMC_RESET_GPIO), > > > + gpio_base + LOONGSON_GPIO_INTEN); > > > + > > > + ret = request_irq(irq, ls2kbmc_interrupt, IRQF_SHARED | > > > IRQF_TRIGGER_FALLING, > > > + "ls2kbmc gpio", priv); > > > + > > > + acpi_unregister_gsi(gsi); > > > + iounmap(gpio_base); > > > + > > > + return ret; > > > +} > > > + > > > +static int ls2kbmc_pdata_initial(struct platform_device *pdev, struct > > > ls2kbmc_pdata *priv) > > > +{ > > > + int ret; > > > + > > > + priv->pdev = *(struct pci_dev **)dev_get_platdata(&pdev->dev); > > > + > > > + ls2kbmc_save_pci_data(priv); > > > + > > > + INIT_WORK(&priv->bmc_work, ls2kbmc_events_fn); > > > + > > > + ret = request_irq(priv->pdev->irq, ls2kbmc_interrupt, > > > + IRQF_SHARED | IRQF_TRIGGER_RISING, "ls2kbmc > > > pcie", priv); > > > + if (ret) { > > > + pr_err("request_irq(%d) failed\n", priv->pdev->irq); > > > + return ret; > > > + } > > > + > > > + return ls2kbmc_gpio_reset_handler(priv); > > > +} > > > + > > > /* > > > * Platform driver > > > */ > > > @@ -598,12 +877,15 @@ static int ls2kbmc_probe(struct platform_device > > > *pdev) > > > if (IS_ERR(priv)) > > > return -ENOMEM; > > > > > > - priv->pdev = *(struct pci_dev **)dev_get_platdata(&pdev->dev); > > > + ret = ls2kbmc_pdata_initial(pdev, priv); > > > + if (ret) > > > + return ret; > > > > > > sdev = ls2kbmc_device_create(&ls2kbmc_driver, pdev, priv); > > > if (IS_ERR(sdev)) > > > return PTR_ERR(sdev); > > > dev = &sdev->dev; > > > + priv->ddev = &sdev->dev; > > > > > > ret = drm_dev_register(dev, 0); > > > if (ret) > > > > -- > > -- > > Thomas Zimmermann > > Graphics Driver Developer > > SUSE Software Solutions Germany GmbH > > Frankenstrasse 146, 90461 Nuernberg, Germany > > GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman > > HRB 36809 (AG Nuernberg) > > > > > -- > Thanks. > Binbin -- Thanks. Binbin
