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 <[email protected]> --- drivers/gpu/drm/tyr/driver.rs | 18 +++++++++--------- drivers/gpu/drm/tyr/gpu.rs | 16 +++++++++------- 2 files changed, 18 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/tyr/driver.rs b/drivers/gpu/drm/tyr/driver.rs index f0da58932702..60d01e3f101b 100644 --- a/drivers/gpu/drm/tyr/driver.rs +++ b/drivers/gpu/drm/tyr/driver.rs @@ -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; @@ -67,19 +68,18 @@ 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"); + if let Err(e) = 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), + ) { dev_err!( dev, - "GPU_INT_RAWSTAT is {}\n", + "GPU reset failed, GPU_IRQ_RAWSTAT is {}\n", regs::GPU_IRQ_RAWSTAT.read(dev, iomem)? ); - - return Err(EIO); + return Err(e); } Ok(()) diff --git a/drivers/gpu/drm/tyr/gpu.rs b/drivers/gpu/drm/tyr/gpu.rs index 6c582910dd5d..2ec56f763cc6 100644 --- a/drivers/gpu/drm/tyr/gpu.rs +++ b/drivers/gpu/drm/tyr/gpu.rs @@ -4,9 +4,10 @@ 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 crate::driver::IoMem; @@ -206,13 +207,14 @@ 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 { + if let Err(e) = poll::read_poll_timeout( + || regs::L2_READY_LO.read(dev, iomem), + |status| *status == 1, + Delta::from_millis(1), + Delta::from_millis(100), + ) { dev_err!(dev, "Failed to power on the GPU\n"); - return Err(EIO); + return Err(e); } Ok(()) -- 2.52.0
