23.01.2019 12:39, Thierry Reding пишет:
From: Thierry Reding treding@nvidia.com
Loading the firmware requires an allocation of IOVA space to make sure that the VIC's Falcon microcontroller can read the firmware if address translation via the SMMU is enabled.
However, the allocation currently happens at a time where the geometry of an IOMMU domain may not have been initialized yet. This happens for example on Tegra186 and later where an ARM SMMU is used. Domains which are created by the ARM SMMU driver postpone the geometry setup until a device is attached to the domain. This is because IOMMU domains aren't attached to a specific IOMMU instance at allocation time and hence the input address space, which defines the geometry, is not known yet.
Work around this by postponing the firmware load until it is needed at the time where a channel is opened to the VIC. At this time the shared IOMMU domain's geometry has been properly initialized.
As a byproduct this allows the Tegra DRM to be created in the absence of VIC firmware, since the VIC initialization no longer fails if the firmware can't be found.
Signed-off-by: Thierry Reding treding@nvidia.com
drivers/gpu/drm/tegra/vic.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c index d47983deb1cf..afbdc33f49bc 100644 --- a/drivers/gpu/drm/tegra/vic.c +++ b/drivers/gpu/drm/tegra/vic.c @@ -181,13 +181,6 @@ static int vic_init(struct host1x_client *client) vic->domain = tegra->domain; }
- if (!vic->falcon.data) {
vic->falcon.data = tegra;err = falcon_load_firmware(&vic->falcon);if (err < 0)goto detach;- }
- vic->channel = host1x_channel_request(client->dev); if (!vic->channel) { err = -ENOMEM;
@@ -256,6 +249,16 @@ static int vic_open_channel(struct tegra_drm_client *client, if (err < 0) return err;
- if (!vic->falcon.data) {
vic->falcon.data = client->drm;err = falcon_load_firmware(&vic->falcon);if (err < 0) {pm_runtime_put(vic->dev);return err;}- }
- err = vic_boot(vic); if (err < 0) { pm_runtime_put(vic->dev);
This only moves the firmware data-copying to a later stage and doesn't touch reading out of the firmware file, hence the claim about the "byproduct" is invalid. Please take a look at the patch I posted sometime ago [0] and feel free to use it as a reference.