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drm/tyr: use read_poll_timeout

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The L2 power-on sequence and soft reset in Tyr previously relied on fixed
sleeps followed by a single register check, since polling helpers were not
available in Rust at the time.

Now that read_poll_timeout() is available, poll the relevant registers
until the hardware reports readiness or a timeout is reached.

This avoids unnecessary delays on start-up.

Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260119202645.362457-1-deborah.brouwer@collabora.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
This commit is contained in:
Deborah Brouwer 2026-01-19 12:26:45 -08:00 committed by Alice Ryhl
parent 793e8f7d52
commit 6ea52b6d8f
2 changed files with 17 additions and 23 deletions
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22
drivers/gpu/drm/tyr/driver.rs
View File

@ -8,6 +8,7 @@
use kernel::devres::Devres;
use kernel::drm;
use kernel::drm::ioctl;
use kernel::io::poll;
use kernel::new_mutex;
use kernel::of;
use kernel::platform;
@ -67,20 +68,13 @@ unsafe impl Sync for TyrData {}
fn issue_soft_reset(dev: &Device<Bound>, iomem: &Devres<IoMem>) -> Result {
regs::GPU_CMD.write(dev, iomem, regs::GPU_CMD_SOFT_RESET)?;
// TODO: We cannot poll, as there is no support in Rust currently, so we
// sleep. Change this when read_poll_timeout() is implemented in Rust.
kernel::time::delay::fsleep(time::Delta::from_millis(100));
if regs::GPU_IRQ_RAWSTAT.read(dev, iomem)? & regs::GPU_IRQ_RAWSTAT_RESET_COMPLETED == 0 {
dev_err!(dev, "GPU reset failed with errno\n");
dev_err!(
dev,
"GPU_IRQ_RAWSTAT is {}\n",
regs::GPU_IRQ_RAWSTAT.read(dev, iomem)?
);
return Err(EIO);
}
poll::read_poll_timeout(
|| regs::GPU_IRQ_RAWSTAT.read(dev, iomem),
|status| *status & regs::GPU_IRQ_RAWSTAT_RESET_COMPLETED != 0,
time::Delta::from_millis(1),
time::Delta::from_millis(100),
)
.inspect_err(|_| dev_err!(dev, "GPU reset failed."))?;
Ok(())
}

18
drivers/gpu/drm/tyr/gpu.rs
View File

@ -6,9 +6,10 @@
use kernel::device::Bound;
use kernel::device::Device;
use kernel::devres::Devres;
use kernel::io::poll;
use kernel::platform;
use kernel::prelude::*;
use kernel::time;
use kernel::time::Delta;
use kernel::transmute::AsBytes;
use kernel::uapi;
@ -204,14 +205,13 @@ fn from(value: u32) -> Self {
pub(crate) fn l2_power_on(dev: &Device<Bound>, iomem: &Devres<IoMem>) -> Result {
regs::L2_PWRON_LO.write(dev, iomem, 1)?;
// TODO: We cannot poll, as there is no support in Rust currently, so we
// sleep. Change this when read_poll_timeout() is implemented in Rust.
kernel::time::delay::fsleep(time::Delta::from_millis(100));
if regs::L2_READY_LO.read(dev, iomem)? != 1 {
dev_err!(dev, "Failed to power on the GPU\n");
return Err(EIO);
}
poll::read_poll_timeout(
|| regs::L2_READY_LO.read(dev, iomem),
|status| *status == 1,
Delta::from_millis(1),
Delta::from_millis(100),
)
.inspect_err(|_| dev_err!(dev, "Failed to power on the GPU."))?;
Ok(())
}