kernel/drivers/usb/host/max3421-hcd.c, branch linux-6.9.y

usb: host: max3421-hcd: Replace snprintf() with the safer scnprintf() variant

2023-12-15T12:55:30Z

There is a general misunderstanding amongst engineers that {v}snprintf() returns the length of the data *actually* encoded into the destination array. However, as per the C99 standard {v}snprintf() really returns the length of the data that *would have been* written if there were enough space for it. This misunderstanding has led to buffer-overruns in the past. It's generally considered safer to use the {v}scnprintf() variants in their place (or even sprintf() in simple cases). So let's do that. Link: https://lwn.net/Articles/69419/ Link: https://github.com/KSPP/linux/issues/105 Cc: Cristian Birsan Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Claudiu Beznea Cc: Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20231213164246.1021885-8-lee@kernel.org Signed-off-by: Greg Kroah-Hartman

usb: host: max3421-hcd: drop of_match_ptr for ID table

2023-03-16T11:15:23Z

The driver can match only via the DT table so the table should be always used and the of_match_ptr does not have any sense (this also allows ACPI matching via PRP0001, even though it might not be relevant here). drivers/usb/host/max3421-hcd.c:1943:34: error: ‘max3421_of_match_table’ defined but not used [-Werror=unused-const-variable=] Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20230311173624.263189-2-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman

usb: max-3421: Fix setting of I/O pins

2023-02-07T07:43:47Z

To update the I/O pins, the registers are read/modified/written. The read operation incorrectly always read the first register. Although wrong, there wasn't any impact as all the output pins are always written, and the inputs are read only anyway. Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.") Signed-off-by: Mark Tomlinson Link: https://lore.kernel.org/r/20230207033337.18112-1-mark.tomlinson@alliedtelesis.co.nz Signed-off-by: Greg Kroah-Hartman

USB: MAX3421: Handle USB NAK correctly

2023-01-31T09:38:05Z

A USB peripheral can respond with a NAK if it is not yet ready to send/receive data. In this case, the transaction should be retried. The MAX3421 driver did do this, and switched to a different type of retry after a number of 'fast' retries. On at least some USB flash devices, this second type of retry never succeeds. This patch changes the behaviour so that 'fast' retries continue. Signed-off-by: Mark Tomlinson Link: https://lore.kernel.org/r/20230127024734.8777-1-mark.tomlinson@alliedtelesis.co.nz Signed-off-by: Greg Kroah-Hartman

usb: max-3421: drop unexpected word "the" in the comments

2022-06-24T11:39:53Z

there is an unexpected word "the" in the comments that need to be dropped file: ./drivers/usb/host/max3421-hcd.c line: 315 * reasonable overview of how control transfers use the the IN/OUT changed to: * reasonable overview of how control transfers use the IN/OUT Signed-off-by: Jiang Jian Link: https://lore.kernel.org/r/20220622103003.5420-1-jiangjian@cdjrlc.com Signed-off-by: Greg Kroah-Hartman

usb: remove third argument of usb_maxpacket()

2022-04-23T08:33:53Z

The third argument of usb_maxpacket(): in_out has been deprecated because it could be derived from the second argument (e.g. using usb_pipeout(pipe)). N.B. function usb_maxpacket() was made variadic to accommodate the transition from the old prototype with three arguments to the new one with only two arguments (so that no renaming is needed). The variadic argument is to be removed once all users of usb_maxpacket() get migrated. CC: Duncan Sands CC: Alan Stern CC: Olav Kongas CC: Rui Miguel Silva Signed-off-by: Vincent Mailhol Link: https://lore.kernel.org/r/20220317035514.6378-7-mailhol.vincent@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

spi: make remove callback a void function

2022-02-09T13:00:45Z

The value returned by an spi driver's remove function is mostly ignored. (Only an error message is printed if the value is non-zero that the error is ignored.) So change the prototype of the remove function to return no value. This way driver authors are not tempted to assume that passing an error to the upper layer is a good idea. All drivers are adapted accordingly. There is no intended change of behaviour, all callbacks were prepared to return 0 before. Signed-off-by: Uwe Kleine-König Acked-by: Marc Kleine-Budde Acked-by: Andy Shevchenko Reviewed-by: Geert Uytterhoeven Acked-by: Jérôme Pouiller Acked-by: Miquel Raynal Acked-by: Jonathan Cameron Acked-by: Claudius Heine Acked-by: Stefan Schmidt Acked-by: Alexandre Belloni Acked-by: Ulf Hansson # For MMC Acked-by: Marcus Folkesson Acked-by: Łukasz Stelmach Acked-by: Lee Jones Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown

usb: max-3421: Use driver data instead of maintaining a list of bound devices

2021-10-21T10:52:28Z

Instead of maintaining a single-linked list of devices that must be searched linearly in .remove() just use spi_set_drvdata() to remember the link between the spi device and the driver struct. Then the global list and the next member can be dropped. This simplifies the driver, reduces the memory footprint and the time to search the list. Also it makes obvious that there is always a corresponding driver struct for a given device in .remove(), so the error path for !max3421_hcd can be dropped, too. As a side effect this fixes a data inconsistency when .probe() races with itself for a second max3421 device in manipulating max3421_hcd_list. A similar race is fixed in .remove(), too. Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.") Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20211018204028.2914597-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

usb: max-3421: Prevent corruption of freed memory

2021-07-21T07:47:15Z

The MAX-3421 USB driver remembers the state of the USB toggles for a device/endpoint. To save SPI writes, this was only done when a new device/endpoint was being used. Unfortunately, if the old device was removed, this would cause writes to freed memory. To fix this, a simpler scheme is used. The toggles are read from hardware when a URB is completed, and the toggles are always written to hardware when any URB transaction is started. This will cause a few more SPI transactions, but no causes kernel panics. Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.") Cc: stable Signed-off-by: Mark Tomlinson Link: https://lore.kernel.org/r/20210625031456.8632-1-mark.tomlinson@alliedtelesis.co.nz Signed-off-by: Greg Kroah-Hartman

sched: Unbreak wakeups

2021-06-18T09:43:06Z

Remove broken task->state references and let wake_up_process() DTRT. The anti-pattern in these patches breaks the ordering of ->state vs COND as described in the comment near set_current_state() and can lead to missed wakeups: (OoO load, observes RUNNING)<-. for (;;) { | t->state = UNINTERRUPTIBLE; | smp_mb(); ,-----> | (observes !COND) | / if (COND) ---------' | COND = 1; break; `- if (t->state != RUNNING) wake_up_process(t); // not done schedule(); // forever waiting } t->state = TASK_RUNNING; Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Davidlohr Bueso Acked-by: Greg Kroah-Hartman Acked-by: Will Deacon Link: https://lore.kernel.org/r/20210611082838.160855222@infradead.org