On Mon, Nov 04, 2024 at 05:42:40PM +0100, Marc Kleine-Budde wrote:
Commit b8e0ddd36ce9 ("can: mcp251xfd: tef: prepare to workaround broken TEF FIFO tail index erratum") introduced mcp251xfd_get_tef_len() to get the number of unhandled transmit events from the Transmit Event FIFO (TEF).
As the TEF has no head pointer, the driver uses the TX FIFO's tail pointer instead, assuming that send frames are completed. However the check for the TEF being full was not correct. This leads to the driver stop working if the TEF is full.
Fix the TEF full check by assuming that if, from the driver's point of view, there are no free TX buffers in the chip and the TX FIFO is empty, all messages must have been sent and the TEF must therefore be full.
Reported-by: Sven Schuchmann schuchmann@schleissheimer.de Closes: https://patch.msgid.link/FR3P281MB155216711EFF900AD9791B7ED9692@FR3P281MB155... Fixes: b8e0ddd36ce9 ("can: mcp251xfd: tef: prepare to workaround broken TEF FIFO tail index erratum") Tested-by: Sven Schuchmann schuchmann@schleissheimer.de Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de
Reviewed-by: Simon Horman horms@kernel.org
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