wireguard-linux/drivers/usb/dwc2/hcd.h, branch jd/unified-crypt-queue

USB: Replace zero-length array with flexible-array member

2020-02-23T18:24:51Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200220132017.GA29262@embeddedor Signed-off-by: Greg Kroah-Hartman

Revert "usb: dwc2: host: Setting qtd to NULL after freeing it"

2019-06-18T08:58:29Z

This reverts commit b0d659022e5c96ee5c4bd62d22d3da2d66de306b. The reverted commit does nothing but adding two unnecessary lines of code. It sets a local variable to NULL in two functions, but that variable is not used anywhere in the rest of those functions. This is just confusing, so let's remove it. Cc: Vardan Mikayelyan Cc: John Youn Cc: Douglas Anderson Cc: Felipe Balbi Acked-by: Minas Harutyunyan Reviewed-by: Douglas Anderson Signed-off-by: Guenter Roeck Signed-off-by: Felipe Balbi

usb: dwc2: host: Fix wMaxPacketSize handling (fix webcam regression)

2019-06-06T10:51:41Z

In commit abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return only packet size") the API to usb_endpoint_maxp() changed. It used to just return wMaxPacketSize but after that commit it returned wMaxPacketSize with the high bits (the multiplier) masked off. If you wanted to get the multiplier it was now up to your code to call the new usb_endpoint_maxp_mult() which was introduced in commit 541b6fe63023 ("usb: add helper to extract bits 12:11 of wMaxPacketSize"). Prior to the API change most host drivers were updated, but no update was made to dwc2. Presumably it was assumed that dwc2 was too simplistic to use the multiplier and thus just didn't support a certain class of USB devices. However, it turns out that dwc2 did use the multiplier and many devices using it were working quite nicely. That means that many USB devices have been broken since the API change. One such device is a Logitech HD Pro Webcam C920. Specifically, though dwc2 didn't directly call usb_endpoint_maxp(), it did call usb_maxpacket() which in turn called usb_endpoint_maxp(). Let's update dwc2 to work properly with the new API. Fixes: abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return only packet size") Cc: stable@vger.kernel.org Acked-by: Minas Harutyunyan Reviewed-by: Matthias Kaehlcke Signed-off-by: Douglas Anderson Signed-off-by: Felipe Balbi

usb: dwc2: host: use hrtimer for NAK retries

2018-12-05T09:13:14Z

Modify the wait delay utilize the high resolution timer API to allow for more precisely scheduled callbacks. A previous commit added a 1ms retry delay after multiple consecutive NAKed transactions using jiffies. On systems with a low timer interrupt frequency, this delay may be significantly longer than specified, resulting in misbehavior with some USB devices. This scenario was reached on a Raspberry Pi 3B with a Macally FDD-USB floppy drive (identified as 0424:0fdc Standard Microsystems Corp. Floppy, based on the USB97CFDC USB FDC). With the relay delay, the drive would be unable to mount a disk, replying with NAKs until the device was reset. Using ktime, the delta between starting the timer (in dwc2_hcd_qh_add) and the callback function can be determined. With the original delay implementation, this value was consistently approximately 12ms. (output in us). -0 [000] ..s. 1600.559974: dwc2_wait_timer_fn: wait_timer delta: 11976 -0 [000] ..s. 1600.571974: dwc2_wait_timer_fn: wait_timer delta: 11977 -0 [000] ..s. 1600.583974: dwc2_wait_timer_fn: wait_timer delta: 11976 -0 [000] ..s. 1600.595974: dwc2_wait_timer_fn: wait_timer delta: 11977 After converting the relay delay to using a higher resolution timer, the delay was much closer to 1ms. -0 [000] d.h. 1956.553017: dwc2_wait_timer_fn: wait_timer delta: 1002 -0 [000] d.h. 1956.554114: dwc2_wait_timer_fn: wait_timer delta: 1002 -0 [000] d.h. 1957.542660: dwc2_wait_timer_fn: wait_timer delta: 1004 -0 [000] d.h. 1957.543701: dwc2_wait_timer_fn: wait_timer delta: 1002 The floppy drive operates properly with delays up to approximately 5ms, and sends NAKs for any delays that are longer. Fixes: 38d2b5fb75c1 ("usb: dwc2: host: Don't retry NAKed transactions right away") Cc: Reviewed-by: Douglas Anderson Acked-by: Minas Harutyunyan Signed-off-by: Terin Stock Signed-off-by: Felipe Balbi

usb: dwc2: Modify dwc2_readl/writel functions prototype

2018-07-30T07:39:16Z

Added hsotg argument to dwc2_readl/writel function prototype, and also instead of address pass offset of register. hsotg will contain flag field for endianness. Also customized dwc2_set_bit and dwc2_clear_bit function for dwc2_readl/writel functions. Signed-off-by: Gevorg Sahakyan Signed-off-by: Felipe Balbi

usb: dwc2: alloc dma aligned buffer for isoc split in

2018-06-19T09:48:13Z

The commit 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in a more supported way") rips out a lot of code to simply the allocation of aligned DMA. However, it also introduces a new issue when use isoc split in transfer. In my test case, I connect the dwc2 controller with an usb hs Hub (GL852G-12), and plug an usb fs audio device (Plantronics headset) into the downstream port of Hub. Then use the usb mic to record, we can find noise when playback. It's because that the usb Hub uses an MDATA for the first transaction and a DATA0 for the second transaction for the isoc split in transaction. An typical isoc split in transaction sequence like this: - SSPLIT IN transaction - CSPLIT IN transaction - MDATA packet - CSPLIT IN transaction - DATA0 packet The DMA address of MDATA (urb->dma) is always DWORD-aligned, but the DMA address of DATA0 (urb->dma + qtd->isoc_split_offset) may not be DWORD-aligned, it depends on the qtd->isoc_split_offset (the length of MDATA). In my test case, the length of MDATA is usually unaligned, this cause DATA0 packet transmission error. This patch use kmem_cache to allocate aligned DMA buf for isoc split in transaction. Note that according to usb 2.0 spec, the maximum data payload size is 1023 bytes for each fs isoc ep, and the maximum allowable interrupt data payload size is 64 bytes or less for fs interrupt ep. So we set the size of object to be 1024 bytes in the kmem cache. Tested-by: Gevorg Sahakyan Tested-by: Heiko Stuebner Acked-by: Minas Harutyunyan hminas@synopsys.com> Signed-off-by: William Wu Reviewed-by: Douglas Anderson Signed-off-by: Felipe Balbi

usb: dwc2: Fix kernel doc's warnings.

2018-05-21T07:02:13Z

Added descriptions for all not described parameters. Fix all kernel doc's warnings. Acked-by: Minas Harutyunyan Signed-off-by: Grigor Tovmasyan Signed-off-by: Felipe Balbi

usb: dwc2: Delete unused functionality

2018-03-13T08:47:42Z

Deleted dwc2_hcd_dump_frrem() function, because it used undefined parameters from dwc2_hsotg structure. The function body was in #ifdef statement and was never compiled. Also removed that parameters from dwc2_hsotg structure, which were used only in dwc2_hcd_dump_frrem() function. And also delete dwc2_sample_frrem macro, because without dwc2_hcd_dump_frrem() function it's lose its purpose. Acked-by: John Youn Signed-off-by: Grigor Tovmasyan Signed-off-by: Felipe Balbi

usb: dwc2: host: Don't retry NAKed transactions right away

2017-12-13T09:27:53Z

On rk3288-veyron devices on Chrome OS it was found that plugging in an Arduino-based USB device could cause the system to lockup, especially if the CPU Frequency was at one of the slower operating points (like 100 MHz / 200 MHz). Upon tracing, I found that the following was happening: * The USB device (full speed) was connected to a high speed hub and then to the rk3288. Thus, we were dealing with split transactions, which is all handled in software on dwc2. * Userspace was initiating a BULK IN transfer * When we sent the SSPLIT (to start the split transaction), we got an ACK. Good. Then we issued the CSPLIT. * When we sent the CSPLIT, we got back a NAK. We immediately (from the interrupt handler) started to retry and sent another SSPLIT. * The device kept NAKing our CSPLIT, so we kept ping-ponging between sending a SSPLIT and a CSPLIT, each time sending from the interrupt handler. * The handling of the interrupts was (because of the low CPU speed and the inefficiency of the dwc2 interrupt handler) was actually taking _longer_ than it took the other side to send the ACK/NAK. Thus we were _always_ in the USB interrupt routine. * The fact that USB interrupts were always going off was preventing other things from happening in the system. This included preventing the system from being able to transition to a higher CPU frequency. As I understand it, there is no requirement to retry super quickly after a NAK, we just have to retry sometime in the future. Thus one solution to the above is to just add a delay between getting a NAK and retrying the transmission. If this delay is sufficiently long to get out of the interrupt routine then the rest of the system will be able to make forward progress. Even a 25 us delay would probably be enough, but we'll be extra conservative and try to delay 1 ms (the exact amount depends on HZ and the accuracy of the jiffy and how close the current jiffy is to ticking, but could be as much as 20 ms or as little as 1 ms). Presumably adding a delay like this could impact the USB throughput, so we only add the delay with repeated NAKs. NOTE: Upon further testing of a pl2303 serial adapter, I found that this fix may help with problems there. Specifically I found that the pl2303 serial adapters tend to respond with a NAK when they have nothing to say and thus we end with this same sequence. Signed-off-by: Douglas Anderson Reviewed-by: Julius Werner Tested-by: Stefan Wahren Acked-by: John Youn Signed-off-by: Felipe Balbi

USB: add SPDX identifiers to all remaining files in drivers/usb/

2017-11-04T10:48:02Z

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/usb/ and include/linux/usb* files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Acked-by: Felipe Balbi Acked-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman