On Mon, Jun 15, 2020 at 10:17:07AM +0200, Marc Kleine-Budde wrote: > On 6/15/20 10:07 AM, Krzysztof Kozlowski wrote: > > If interrupt comes late, during probe error path or device remove (could > > be triggered with CONFIG_DEBUG_SHIRQ), the interrupt handler > > dspi_interrupt() will access registers with the clock being disabled. This > > leads to external abort on non-linefetch on Toradex Colibri VF50 module > > (with Vybrid VF5xx): > > Unhandled fault: external abort on non-linefetch (0x1008) at 0x8887f02c > > Internal error: : 1008 [#1] ARM > > CPU: 0 PID: 136 Comm: sh Not tainted 5.7.0-next-20200610-00009-g5c913fa0f9c5-dirty #74 > > Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree) > > (regmap_mmio_read32le) from [<8061885c>] (regmap_mmio_read+0x48/0x68) > > (regmap_mmio_read) from [<8060e3b8>] (_regmap_bus_reg_read+0x24/0x28) > > (_regmap_bus_reg_read) from [<80611c50>] (_regmap_read+0x70/0x1c0) Please think hard before including complete backtraces in upstream reports, they are very large and contain almost no useful information relative to their size so often obscure the relevant content in your message. If part of the backtrace is usefully illustrative (it often is for search engines if nothing else) then it's usually better to pull out the relevant sections. > > +disable_irq: > > + if (dspi->irq > 0) > > + disable_irq(dspi->irq); > What happens, if you re-bind the driver? > Is the IRQ still working? > Who is taking care of calling the enable_irq() again? > What happens, if you really have a shared IRQ line? > Is the IRQ disabled for all other devices on the same IRQ line? Indeed. The upshot of all this is that the interrupt needs to be freed not disabled before the clocks are disabled, or some other mechanism needs to be used to ensure that the interrupt handler won't attempt to access the hardware when it shouldn't. As Vladimir says there are serious issues using devm for interrupt handlers (or anything else that might cause code to be run) due to problems like this.
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