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Devin Wittmayer
7825de3f75
Some laptops carry a MediaTek power table in their firmware, and the driver reads it to set a transmit limit for each frequency range. It only fills in the ranges themselves when it registers the device. The startup step that does this existed already, but it never programmed anything. Two recent commits made it run a regulatory update instead, which sets the limits on the way through, long before registration. As a result, on a machine that has the table the driver reads through an empty pointer and the interface never appears: BUG: kernel NULL pointer dereference, address: 0000000000000004 RIP: 0010:mt792x_init_acpi_sar_power Call Trace: mt7921_set_tx_sar_pwr mt7921_mcu_regd_update mt7921_regd_update mt7921_run_firmware mt7921e_mcu_init mt7921_init_work Skip it when the ranges are missing. They are applied again once the device is up, which is where they came from before. Reported-by: Klara Modin <klarasmodin@gmail.com> Closes: https://lore.kernel.org/linux-wireless/aoyxqHYvSuaBeubf@soda.int.kasm.eu/ Fixes:9b80bd9cab("wifi: mt76: mt7921: add regulatory wiphy self manager support") Fixes:e9f3f1cc13("wifi: mt76: mt7925: add regulatory wiphy self manager support") Signed-off-by: Devin Wittmayer <lucid_duck@justthetip.ca> Tested-by: David Gow <david@davidgow.net> Tested-by: Klara Modin <klarasmodin@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>