can: gs_usb: add usb quirk for NXP LPC546xx controllers
Introduce a workaround for a NXP chip errata on LPC546xx controllers (Errata sheet LPC546xx / USB.15). According to the document corruption can occur when the following conditions are met: * A TX (IN) transfer happens after a RX (OUT) transfer. * The RX (OUT) transfer length is 4 + N * 16 (N >= 0) bytes. Even though the struct gs_host_frame has a size of 76 bytes for a FD frame, which does not apply to the above rule, corruption could be seen. Adding a dummy byte to break the second condition also on transfer lengths with 4 + N * 8 bytes reliably circumvents USB transfer data corruption. The firmware can now request this quirk by setting GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX. Link: https://lore.kernel.org/all/20220309124132.291861-17-mkl@pengutronix.de Signed-off-by: Peter Fink <pfink@christ-es.de> Signed-off-by: Christoph Möhring <cmoehring@christ-es.de> Signed-off-by: Alexander Schartner <aschartner@christ-es.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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