cdns3_ep_onc...ffer_reserve(9)

✨ cdns3_ep_onchip_buffer_reserve(9) — the kernel API manual 💅

okay so bestie, welcome to the cdns3_ep_onc...ffer_reserve(9) page from the Kernel API Manual 🦋 this one's a little cutie from the USB gadget world and honestly she's giving "gatekeeper of the on-chip buffers" energy 👑

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🌸 NAME 🌸

cdns3_ep_onchip_buffer_reserve — literally just "try to reserve onchip buf for EP" 💖 that's it, that's the whole vibe.

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✨ SYNOPSIS ✨

int cdns3_ep_onchip_buffer_reserve (struct cdns3_device *priv_dev , int
size , int is_in );

three args, one int coming back at you, no cap 🔥

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🎀 ARGUMENTS 🎀

• priv_dev — the extended gadget object 🫶 like, the whole device situation
• size — the size (KB) for EP would like to allocate 🍓 yes KB, keep that in mind bestie, don't come in here thinking bytes
• is_in — endpoint direction 🌈 which way the data's headed

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💜 DESCRIPTION 💜

okay so here's the tea ☕ this function is not the one actually doing the reserving. the real reservation will occur during write to EP_CFG register — so this one is basically the vibe check ✨ it's used to check if the size reservation is allowed 👀

think of her as the bouncer at the club, not the one handing out the drinks girlie 💅

she's gonna Return 0 if the required size can met or negative value on failure 😭 so yeah, 0 = we slay, negative = we do not slay, check your size again bestie 🧚

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🔥 SEE ALSO 🔥

the kernel file lives at ./drivers/usb/cdns3/cdns3-gadget.c 📁 and here's the whole friend group, everybody in the group chat, not a single one left out 💖:

• cdns3_clear_register_bit(9)
• cdns3_set_register_bit(9)
• cdns3_ep_addr_to_index(9)
• cdns3_next_request(9)
• cdns3_next_align_buf(9)
• cdns3_next_priv_request(9)
• cdns3_select_ep(9)
• cdns3_get_tdl(9)
• cdns3_allocate_trb_pool(9)
• cdns3_ep_stall_flush(9)
• cdns3_hw_reset_eps_config(9)
• cdns3_ep_inc_trb(9)
• cdns3_ep_inc_enq(9)
• cdns3_ep_inc_deq(9)
• cdns3_allow_enable_l1(9)
• cdns3_start_all_request(9)
• cdns3_wa2_descmiss_copy_data(9)
• cdns3_wa2_descmissing_packet(9)
• cdns3_gadget_giveback(9)
• cdns3_ep_run_transfer(9)
• cdns3_trb_handled(9)
• cdns3_check_ep_interrupt_proceed(9)
• cdns3_check_usb_interrupt_proceed(9)
• cdns3_device_irq_handler(9)
• cdns3_device_thread_irq_handler(9)
• cdns3_ep_config(9)
• cdns3_gadget_ep_alloc_request(9)
• cdns3_gadget_ep_free_request(9)
• cdns3_gadget_ep_enable(9)
• cdns3_gadget_ep_disable(9)
• __cdns3_gadget_ep_queue(9)
• cdns3_gadget_ep_dequeue(9)
• __cdns3_gadget_ep_set_halt(9)
• __cdns3_gadget_ep_clear_halt(9)
• cdns3_gadget_ep_set_halt(9)
• cdns3_gadget_get_frame(9)
• cdns3_gadget_udc_start(9)
• cdns3_gadget_udc_stop(9)
• cdns3_gadget_check_config(9)
• cdns3_init_eps(9)
• cdns3_gadget_init(9)

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ok real talk before you go 🫶 this page is filed under ./drivers/usb/cdns3 and it's dated October 2026, and the whole thing is literally called cdns3_ep_onc...ffer_reserve(9) — yes the title is truncated with ..., no that's not a typo, that's just how the manpage renders it 💀 go read the others, ily, bye 💜✨