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由 Serge Semin 提交于
stable inclusion from stable-5.10.7 commit 97abe6663fa35c40edb2efebdc3aea8bad71086c bugzilla: 47429 -------------------------------- commit fca3f138 upstream. Originally the procedure of the ULPI transaction finish detection has been developed as a simple busy-loop with just decrementing counter and no delays. It's wrong since on different systems the loop will take a different time to complete. So if the system bus and CPU are fast enough to overtake the ULPI bus and the companion PHY reaction, then we'll get to take a false timeout error. Fix this by converting the busy-loop procedure to take the standard bus speed, address value and the registers access mode into account for the busy-loop delay calculation. Here is the way the fix works. It's known that the ULPI bus is clocked with 60MHz signal. In accordance with [1] the ULPI bus protocol is created so to spend 5 and 6 clock periods for immediate register write and read operations respectively, and 6 and 7 clock periods - for the extended register writes and reads. Based on that we can easily pre-calculate the time which will be needed for the controller to perform a requested IO operation. Note we'll still preserve the attempts counter in case if the DWC USB3 controller has got some internals delays. [1] UTMI+ Low Pin Interface (ULPI) Specification, Revision 1.1, October 20, 2004, pp. 30 - 36. Fixes: 88bc9d19 ("usb: dwc3: add ULPI interface support") Acked-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru> Link: https://lore.kernel.org/r/20201210085008.13264-3-Sergey.Semin@baikalelectronics.ru Cc: stable <stable@vger.kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: NChen Jun <chenjun102@huawei.com> Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
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