On Mon, 22 May 2023, Matt Roper <matthew.d.roper@xxxxxxxxx> wrote:
> For platforms with GMD_ID support (i.e., everything MTL and beyond),
> identification of the display IP present should be based on the contents
> of the GMD_ID register rather than a PCI devid match.
>
> Note that since GMD_ID readout requires access to the PCI BAR, a slight
> change to the driver init sequence is needed --- pci_enable_device() is
> now called before i915_driver_create().
>
> v2:
> - Fix use of uninitialized i915 pointer in error path if
> pci_enable_device() fails before the i915 device is created. (lkp)
> - Use drm_device parameter to intel_display_device_probe. This goes
> against i915 conventions, but since the primary goal here is to make
> it easy to call this function from other drivers (like Xe) and since
> we don't need anything from the i915 structure, this seems like an
> exception where drm_device is a more natural fit.
>
> Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
> ---
> .../drm/i915/display/intel_display_device.c | 64 +++++++++++++++++--
> .../drm/i915/display/intel_display_device.h | 5 +-
> drivers/gpu/drm/i915/i915_driver.c | 17 +++--
> drivers/gpu/drm/i915/intel_device_info.c | 12 ++--
> 4 files changed, 81 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index 3c5941c8788d..6605487c3890 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -6,7 +6,10 @@
> #include <drm/i915_pciids.h>
> #include <drm/drm_color_mgmt.h>
> #include <linux/mod_devicetable.h>
> +#include <linux/pci.h>
>
> +#include "i915_drv.h"
> +#include "i915_reg.h"
> #include "intel_display_device.h"
> #include "intel_display_power.h"
> #include "intel_display_reg_defs.h"
> @@ -692,18 +695,69 @@ static const struct pci_device_id intel_display_ids[] = {
> INTEL_RPLP_IDS(&xe_lpd_display),
> INTEL_DG2_IDS(&xe_hpd_display),
>
> - /* FIXME: Replace this with a GMD_ID lookup */
> - INTEL_MTL_IDS(&xe_lpdp_display),
> + /*
> + * Do not add any GMD_ID-based platforms to this list. They will
> + * be probed automatically based on the IP version reported by
> + * the hardware.
> + */
> };
>
> +struct {
> + u16 ver;
> + u16 rel;
> + const struct intel_display_device_info *display;
> +} gmdid_display_map[] = {
> + { 14, 0, &xe_lpdp_display },
> +};
> +
> +static const struct intel_display_device_info *
> +probe_gmdid_display(struct drm_device *drm, u16 *ver, u16 *rel, u16 *step)
Please always prefer struct drm_i915_private * over struct drm_device *.
> +{
> + struct pci_dev *pdev = to_pci_dev(drm->dev);
> + void __iomem *addr;
> + u32 val;
> + int i;
> +
> + addr = pci_iomap_range(pdev, 0, i915_mmio_reg_offset(GMD_ID_DISPLAY), sizeof(u32));
> + if (!addr) {
> + drm_err(drm, "Cannot map MMIO BAR to read display GMD_ID\n");
> + return &no_display;
> + }
> +
> + val = ioread32(addr);
> + pci_iounmap(pdev, addr);
> +
> + if (val == 0)
> + /* Platform doesn't have display */
> + return &no_display;
> +
> + *ver = REG_FIELD_GET(GMD_ID_ARCH_MASK, val);
> + *rel = REG_FIELD_GET(GMD_ID_RELEASE_MASK, val);
> + *step = REG_FIELD_GET(GMD_ID_STEP, val);
> +
> + for (i = 0; i < ARRAY_SIZE(gmdid_display_map); i++)
> + if (*ver == gmdid_display_map[i].ver &&
> + *rel == gmdid_display_map[i].rel)
> + return gmdid_display_map[i].display;
> +
> + drm_err(drm, "Unrecognized display IP version %d.%02d; disabling display.\n",
> + *ver, *rel);
> + return &no_display;
> +}
> +
> const struct intel_display_device_info *
> -intel_display_device_probe(u16 pci_devid)
> +intel_display_device_probe(struct drm_device *drm, bool has_gmdid,
> + u16 *gmdid_ver, u16 *gmdid_rel, u16 *gmdid_step)
Ditto.
> {
> + struct pci_dev *pdev = to_pci_dev(drm->dev);
> int i;
>
> + if (has_gmdid)
> + return probe_gmdid_display(drm, gmdid_ver, gmdid_rel, gmdid_step);
> +
> for (i = 0; i < ARRAY_SIZE(intel_display_ids); i++) {
> - if (intel_display_ids[i].device == pci_devid)
> - return (struct intel_display_device_info *)intel_display_ids[i].driver_data;
> + if (intel_display_ids[i].device == pdev->device)
> + return (const struct intel_display_device_info *)intel_display_ids[i].driver_data;
> }
>
> return &no_display;
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
> index 1f7d08b3ad6b..2a14943313ad 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
> @@ -80,7 +80,10 @@ struct intel_display_device_info {
> } color;
> };
>
> +struct drm_device;
> +
Please keep forward declarations near the top of the file, right after
includes.
> const struct intel_display_device_info *
> -intel_display_device_probe(u16 pci_devid);
> +intel_display_device_probe(struct drm_device *drm, bool has_gmdid,
> + u16 *ver, u16 *rel, u16 *step);
>
> #endif
> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
> index 522733a89946..37532e55327d 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -754,13 +754,17 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> struct drm_i915_private *i915;
> int ret;
>
> - i915 = i915_driver_create(pdev, ent);
> - if (IS_ERR(i915))
> - return PTR_ERR(i915);
> -
> ret = pci_enable_device(pdev);
> - if (ret)
> - goto out_fini;
> + if (ret) {
> + pr_err("Failed to enable graphics device: %pe\n", ERR_PTR(ret));
> + return ret;
> + }
> +
> + i915 = i915_driver_create(pdev, ent);
> + if (IS_ERR(i915)) {
> + ret = PTR_ERR(i915);
> + goto out_pci_disable;
> + }
>
> ret = i915_driver_early_probe(i915);
> if (ret < 0)
> @@ -843,7 +847,6 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> i915_driver_late_release(i915);
> out_pci_disable:
> pci_disable_device(pdev);
> -out_fini:
> i915_probe_error(i915, "Device initialization failed (%d)\n", ret);
> return ret;
> }
> diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
> index e1507ae59f2d..85105639d55d 100644
> --- a/drivers/gpu/drm/i915/intel_device_info.c
> +++ b/drivers/gpu/drm/i915/intel_device_info.c
> @@ -345,7 +345,6 @@ static void ip_ver_read(struct drm_i915_private *i915, u32 offset, struct intel_
> static void intel_ipver_early_init(struct drm_i915_private *i915)
> {
> struct intel_runtime_info *runtime = RUNTIME_INFO(i915);
> - struct intel_display_runtime_info *display_runtime = DISPLAY_RUNTIME_INFO(i915);
>
> if (!HAS_GMD_ID(i915)) {
> drm_WARN_ON(&i915->drm, RUNTIME_INFO(i915)->graphics.ip.ver > 12);
> @@ -366,8 +365,6 @@ static void intel_ipver_early_init(struct drm_i915_private *i915)
> RUNTIME_INFO(i915)->graphics.ip.ver = 12;
> RUNTIME_INFO(i915)->graphics.ip.rel = 70;
> }
> - ip_ver_read(i915, i915_mmio_reg_offset(GMD_ID_DISPLAY),
> - (struct intel_ip_version *)&display_runtime->ip);
> ip_ver_read(i915, i915_mmio_reg_offset(GMD_ID_MEDIA),
> &runtime->media.ip);
> }
> @@ -574,6 +571,7 @@ void intel_device_info_driver_create(struct drm_i915_private *i915,
> {
> struct intel_device_info *info;
> struct intel_runtime_info *runtime;
> + u16 ver, rel, step;
>
> /* Setup the write-once "constant" device info */
> info = mkwrite_device_info(i915);
> @@ -584,8 +582,14 @@ void intel_device_info_driver_create(struct drm_i915_private *i915,
> memcpy(runtime, &INTEL_INFO(i915)->__runtime, sizeof(*runtime));
>
> /* Probe display support */
> - info->display = intel_display_device_probe(device_id);
> + info->display = intel_display_device_probe(&i915->drm, info->has_gmd_id,
> + &ver, &rel, &step);
> *DISPLAY_RUNTIME_INFO(i915) = DISPLAY_INFO(i915)->__runtime_defaults;
> + if (info->has_gmd_id) {
> + DISPLAY_RUNTIME_INFO(i915)->ip.ver = ver;
> + DISPLAY_RUNTIME_INFO(i915)->ip.rel = rel;
> + DISPLAY_RUNTIME_INFO(i915)->ip.step = step;
> + }
The division of initialization responsibilities between here and
intel_display_device_probe() is perhaps a bit odd?
Nothing that can't be fixed later though, I guess.
BR,
Jani.
>
> runtime->device_id = device_id;
> }
--
Jani Nikula, Intel Open Source Graphics Center
