kernel/linux.git/drivers/usb/gadget/udc, branch linux-7.0.y

USB: omap_udc: DMA: Don't enable burst 4 mode

2026-05-14T13:31:04+00:00

commit 3f91484f6c13c434bd573ca6b6779c26adb0ddab upstream. Commit 65111084c63d7 ("USB: more omap_udc updates (dma and omap1710)") added setting for DMA burst 4 mode. But I think this should be undone for two reasons: - It breaks DMA on 15xx boards - transfers just silently stall. - On newer OMAP1 boards, like Nokia 770 (omap1710), there is no measurable performance impact when testing TCP throughput with g_ether with large 15000 byte MTU size. It's also worth noting that when the original change was made, the OMAP_DMA_DATA_BURST_4 handling in arch/arm/plat-omap/dma.c was broken, and actually resulted in the same as the OMAP_DMA_DATA_BURST_DIS i.e. burst disabled. This was fixed not until a couple kernel releases later in an unrelated commit 1a8bfa1eb998a ("[ARM] 3142/1: OMAP 2/5: Update files common to omap1 and omap2"). So based on this it seems there was never really a very good reason to enable this burst mode in omap_udc, so remove it now to allow 15xx DMA to work again (it provides 2x throughput compared to PIO mode). Fixes: 65111084c63d ("[PATCH] USB: more omap_udc updates (dma and omap1710)") Cc: stable Signed-off-by: Aaro Koskinen Link: https://patch.msgid.link/ad06qHLclWHeSGnV@darkstar.musicnaut.iki.fi Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

usb: gadget: renesas_usb3: validate endpoint index in standard request handlers

2026-04-22T11:32:16+00:00

commit f880aac8a57ebd92abfa685d45424b2998ac1059 upstream. The GET_STATUS and SET/CLEAR_FEATURE handlers extract the endpoint number from the host-supplied wIndex without any sort of validation. Fix this up by validating the number of endpoints actually match up with the number the device has before attempting to dereference a pointer based on this math. This is just like what was done in commit ee0d382feb44 ("usb: gadget: aspeed_udc: validate endpoint index for ast udc") for the aspeed driver. Fixes: 746bfe63bba3 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller") Cc: stable Assisted-by: gregkh_clanker_t1000 Link: https://patch.msgid.link/2026040647-sincerity-untidy-b104@gregkh Signed-off-by: Greg Kroah-Hartman

usb: gadget: dummy_hcd: fix premature URB completion when ZLP follows partial transfer

2026-03-18T15:19:33+00:00

When a gadget request is only partially transferred in transfer() because the per-frame bandwidth budget is exhausted, the loop advances to the next queued request. If that next request is a zero-length packet (ZLP), len evaluates to zero and the code takes the unlikely(len == 0) path, which sets is_short = 1. This bypasses the bandwidth guard ("limit < ep->ep.maxpacket && limit < len") that lives in the else branch and would otherwise break out of the loop for non-zero requests. The is_short path then completes the URB before all data from the first request has been transferred. Reproducer (bulk IN, high speed): Device side (FunctionFS with Linux AIO): 1. Queue a 65024-byte write via io_submit (127 * 512, i.e. a multiple of the HS bulk max packet size). 2. Immediately queue a zero-length write (ZLP) via io_submit. Host side: 3. Submit a 65536-byte bulk IN URB. Expected: URB completes with actual_length = 65024. Actual: URB completes with actual_length = 53248, losing 11776 bytes that leak into subsequent URBs. At high speed the per-frame budget is 53248 bytes (512 * 13 * 8). The 65024-byte request exhausts this budget after 53248 bytes, leaving the request incomplete (req->req.actual < req->req.length). Neither the request nor the URB is finished, and rescan is 0, so the loop advances to the ZLP. For the ZLP, dev_len = 0, so len = min(12288, 0) = 0, taking the unlikely(len == 0) path and setting is_short = 1. The is_short handler then sets *status = 0, completing the URB with only 53248 of the expected 65024 bytes. Fix this by breaking out of the loop when the current request has remaining data (req->req.actual < req->req.length). The request resumes on the next timer tick, preserving correct data ordering. Signed-off-by: Sebastian Urban Cc: stable Reviewed-by: Alan Stern Link: https://patch.msgid.link/20260315151045.1155850-1-surban@surban.net Signed-off-by: Greg Kroah-Hartman

USB: dummy-hcd: Fix interrupt synchronization error

2026-03-18T15:16:33+00:00

This fixes an error in synchronization in the dummy-hcd driver. The error has a somewhat involved history. The synchronization mechanism was introduced by commit 7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous synchronization change"), which added an emulated "interrupts enabled" flag together with code emulating synchronize_irq() (it waits until all current handler callbacks have returned). But the emulated interrupt-disable occurred too late, after the driver containing the handler callback routines had been told that it was unbound and no more callbacks would occur. Commit 4a5d797a9f9c ("usb: gadget: dummy_hcd: fix gpf in gadget_setup") tried to fix this by moving the synchronize_irq() emulation code from dummy_stop() to dummy_pullup(), which runs before the unbind callback. There still were races, though, because the emulated interrupt-disable still occurred too late. It couldn't be moved to dummy_pullup(), because that routine can be called for reasons other than an impending unbind. Therefore commits 7dc0c55e9f30 ("USB: UDC core: Add udc_async_callbacks gadget op") and 04145a03db9d ("USB: UDC: Implement udc_async_callbacks in dummy-hcd") added an API allowing the UDC core to tell dummy-hcd exactly when emulated interrupts and their callbacks should be disabled. That brings us to the current state of things, which is still wrong because the emulated synchronize_irq() occurs before the emulated interrupt-disable! That's no good, beause it means that more emulated interrupts can occur after the synchronize_irq() emulation has run, leading to the possibility that a callback handler may be running when the gadget driver is unbound. To fix this, we have to move the synchronize_irq() emulation code yet again, to the dummy_udc_async_callbacks() routine, which takes care of enabling and disabling emulated interrupt requests. The synchronization will now run immediately after emulated interrupts are disabled, which is where it belongs. Signed-off-by: Alan Stern Fixes: 04145a03db9d ("USB: UDC: Implement udc_async_callbacks in dummy-hcd") Cc: stable Link: https://patch.msgid.link/c7bc93fe-4241-4d04-bd56-27c12ba35c97@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

USB: dummy-hcd: Fix locking/synchronization error

2026-03-18T15:16:29+00:00

Syzbot testing was able to provoke an addressing exception and crash in the usb_gadget_udc_reset() routine in drivers/usb/gadgets/udc/core.c, resulting from the fact that the routine was called with a second ("driver") argument of NULL. The bad caller was set_link_state() in dummy_hcd.c, and the problem arose because of a race between a USB reset and driver unbind. These sorts of races were not supposed to be possible; commit 7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous synchronization change"), along with a few followup commits, was written specifically to prevent them. As it turns out, there are (at least) two errors remaining in the code. Another patch will address the second error; this one is concerned with the first. The error responsible for the syzbot crash occurred because the stop_activity() routine will sometimes drop and then re-acquire the dum->lock spinlock. A call to stop_activity() occurs in set_link_state() when handling an emulated USB reset, after the test of dum->ints_enabled and before the increment of dum->callback_usage. This allowed another thread (doing a driver unbind) to sneak in and grab the spinlock, and then clear dum->ints_enabled and dum->driver. Normally this other thread would have to wait for dum->callback_usage to go down to 0 before it would clear dum->driver, but in this case it didn't have to wait since dum->callback_usage had not yet been incremented. The fix is to increment dum->callback_usage _before_ calling stop_activity() instead of after. Then the thread doing the unbind will not clear dum->driver until after the call to usb_gadget_udc_reset() safely returns and dum->callback_usage has been decremented again. Signed-off-by: Alan Stern Reported-by: syzbot+19bed92c97bee999e5db@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/68fc7c9c.050a0220.346f24.023c.GAE@google.com/ Tested-by: syzbot+19bed92c97bee999e5db@syzkaller.appspotmail.com Fixes: 7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous synchronization change") Cc: stable Link: https://patch.msgid.link/46135f42-fdbe-46b5-aac0-6ca70492af15@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

usb: gadget: tegra-xudc: Add handling for BLCG_COREPLL_PWRDN

2026-01-27T14:51:58+00:00

The COREPLL_PWRDN bit in the BLCG register must be set when the XUSB device controller is powergated and cleared when it is unpowergated. If this bit is not explicitly controlled, the core PLL may remain in an incorrect power state across suspend/resume or ELPG transitions. Therefore, update the driver to explicitly control this bit during powergate transitions. Fixes: 49db427232fe ("usb: gadget: Add UDC driver for tegra XUSB device mode controller") Cc: stable Signed-off-by: Haotien Hsu Signed-off-by: Wayne Chang Link: https://patch.msgid.link/20260123173121.4093902-1-waynec@nvidia.com Signed-off-by: Greg Kroah-Hartman

usb: bdc: fix sleep during atomic

2026-01-23T16:16:31+00:00

bdc_run() can be ran during atomic context leading to a sleep during atomic warning. Fix this by replacing read_poll_timeout() with read_poll_timeout_atomic(). Fixes: 75ae051efc9b ("usb: gadget: bdc: use readl_poll_timeout() to simplify code") Signed-off-by: Justin Chen Reviewed-by: Florian Fainelli Link: https://patch.msgid.link/20260120200754.2488765-1-justin.chen@broadcom.com Signed-off-by: Greg Kroah-Hartman