diff options
| author | Niklas Neronin <niklas.neronin@linux.intel.com> | 2025-05-15 16:56:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-21 12:35:32 +0200 |
| commit | 1711b255484a1a0613a194ca7897efba6db17159 (patch) | |
| tree | 793e1bc6dd8c71ccbe590ac40a41720bb743a944 /drivers/usb/host/xhci.c | |
| parent | 743cb737a62fc22d1e472bc07258a6f8430a399c (diff) | |
usb: xhci: refactor xhci_set_cmd_ring_deq()
Refactor xhci_set_cmd_ring_deq() making the code more understandable by
using more descriptive constants and separating operations logically.
- Remove 'CMD_RING_RSVD_BITS' the macro is misleading, the reserved bits
are 5:4, yet the mask is for bits 5:0.
- Introduce masks 'CMD_RING_PTR_MASK' and 'CMD_RING_CYCLE' to clearly
define the bits for the Command Ring pointer and Command Ring Cycle.
- Simplifying the process of setting the command ring address by separating
the DMA address calculation and the Command Ring Control register (crcr)
updates.
- Remove the "// " prefix from trace messages, as it is unnecessary and
distracting.
Note: In the current implementation, the cycle bit is not cleared before
applying the OR operation. Although this hasn't caused issues so far
because the bit is '0' before reaching this function, the bit is now
cleared before being set to prevent potential future problems and simplify
the process.
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250515135621.335595-7-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 66a9106d8b31..4c9174c5c7c7 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -497,19 +497,21 @@ static void xhci_enable_max_dev_slots(struct xhci_hcd *xhci) static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci) { - u64 val_64; - - /* step 2: initialize command ring buffer */ - val_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring); - val_64 = (val_64 & (u64) CMD_RING_RSVD_BITS) | - (xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg, - xhci->cmd_ring->dequeue) & - (u64) ~CMD_RING_RSVD_BITS) | - xhci->cmd_ring->cycle_state; - xhci_dbg_trace(xhci, trace_xhci_dbg_init, - "// Setting command ring address to 0x%llx", - (unsigned long long) val_64); - xhci_write_64(xhci, val_64, &xhci->op_regs->cmd_ring); + dma_addr_t deq_dma; + u64 crcr; + + deq_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg, xhci->cmd_ring->dequeue); + deq_dma &= CMD_RING_PTR_MASK; + + crcr = xhci_read_64(xhci, &xhci->op_regs->cmd_ring); + crcr &= ~CMD_RING_PTR_MASK; + crcr |= deq_dma; + + crcr &= ~CMD_RING_CYCLE; + crcr |= xhci->cmd_ring->cycle_state; + + xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Setting command ring address to 0x%llx", crcr); + xhci_write_64(xhci, crcr, &xhci->op_regs->cmd_ring); } /* |