Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
Pre-existing issues: - [High] This problem wasn't introduced by this patch, but a sleeping function `readl_poll_timeout` is used in a display driver function designed to be called from the atomic commit path. - [High] This problem wasn't introduced by this patch, but the return value of `pm_runtime_get_sync()` is ignored, leading to unclocked hardware register access on failure. -- commit e147aed08964b1f246d1a5b035f162b665564efa Author: Guangshuo Li <[email protected]> gpu: ipu-v3: prg: fix clock cleanup on remove ipu_prg_probe() enables the IPG and AXI clocks before enabling runtime PM. The clocks are subsequently controlled by the runtime suspend and resume callbacks. > diff --git a/drivers/gpu/ipu-v3/ipu-prg.c b/drivers/gpu/ipu-v3/ipu-prg.c > index d38d3ba54d722..93033e847d0e5 100644 > --- a/drivers/gpu/ipu-v3/ipu-prg.c > +++ b/drivers/gpu/ipu-v3/ipu-prg.c [ ... ] While reviewing this file, I noticed a few pre-existing issues regarding runtime PM and atomic context that might be worth addressing. drivers/gpu/ipu-v3/ipu-prg.c:ipu_prg_channel_disable() { ... pm_runtime_get_sync(prg->dev); val = readl(prg->regs + IPU_PRG_CTL); val |= IPU_PRG_CTL_BYPASS(prg_chan); writel(val, prg->regs + IPU_PRG_CTL); ... } [Severity: High] This isn't a bug introduced by this patch, but the return value of pm_runtime_get_sync() is ignored, leading to potential unclocked hardware register access on failure. If clk_prepare_enable() fails during resume, the clocks remain disabled. Is it possible for the hardware to trigger a Synchronous External Abort (AXI bus error) and a kernel panic when readl() and writel() unconditionally access the unclocked registers immediately after? The same pattern also exists in ipu_prg_channel_configure(): drivers/gpu/ipu-v3/ipu-prg.c:ipu_prg_channel_configure() { ... pm_runtime_get_sync(prg->dev); val = (stride - 1) & IPU_PRG_STRIDE_STRIDE_MASK; writel(val, prg->regs + IPU_PRG_STRIDE(prg_chan)); ... } [Severity: High] This isn't a bug introduced by this patch, but the return value of pm_runtime_get_sync() is also ignored here. Should we check the return value and handle the error to prevent unclocked access? drivers/gpu/ipu-v3/ipu-prg.c:ipu_prg_channel_configure() { ... /* wait for both double buffers to be filled */ readl_poll_timeout(prg->regs + IPU_PRG_STATUS, val, (val & IPU_PRG_STATUS_BUFFER0_READY(prg_chan)) && (val & IPU_PRG_STATUS_BUFFER1_READY(prg_chan)), 5, 1000); ... } [Severity: High] This isn't a bug introduced by this patch, but a sleeping function readl_poll_timeout() is used in a display driver function designed to be called from the atomic commit path. ipu_prg_channel_configure() is called from ipu_plane_atomic_update(), which is a plane atomic update callback. Since readl_poll_timeout() internally calls usleep_range() and will sleep, could this trigger might_sleep() warnings or deadlocks in the atomic commit path? Should readl_poll_timeout_atomic() be used here instead? -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=1
