firewire: ohci: code refactoring to use union for isoc multiple channel state

In 1394 OHCI driver, some members of struct iso_context are only used for
multi-channel isochronous contexts.

This commit uses a union for these members to clearly separate
multi-channel specific state.

Link: https://lore.kernel.org/r/20260117142823.440811-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index b1dc0c4feb8664b7a5aafe107a7340faab02a518..5d9857cbbd24ec5efe2d858d694a7917cfe68de0 100644 (file)
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -169,8 +169,6 @@ struct iso_context {
        struct fw_iso_context base;
        struct context context;
        unsigned long flushing_completions;
-       u32 mc_buffer_bus;
-       u16 mc_completed;
        u8 sync;
        u8 tags;
        union {
@@ -179,6 +177,10 @@ struct iso_context {
                        size_t header_length;
                        void *header;
                } sc;
+               struct {
+                       u32 buffer_bus;
+                       u16 completed;
+               } mc;
        };
 };
 
@@ -2826,8 +2828,8 @@ static int handle_ir_buffer_fill(struct context *context,
        buffer_dma = le32_to_cpu(last->data_address);
 
        if (completed > 0) {
-               ctx->mc_buffer_bus = buffer_dma;
-               ctx->mc_completed = completed;
+               ctx->mc.buffer_bus = buffer_dma;
+               ctx->mc.completed = completed;
        }
 
        if (res_count != 0)
@@ -2846,7 +2848,7 @@ static int handle_ir_buffer_fill(struct context *context,
                ctx->base.callback.mc(&ctx->base,
                                      buffer_dma + completed,
                                      ctx->base.callback_data);
-               ctx->mc_completed = 0;
+               ctx->mc.completed = 0;
        }
 
        return 1;
@@ -2855,17 +2857,16 @@ static int handle_ir_buffer_fill(struct context *context,
 static void flush_ir_buffer_fill(struct iso_context *ctx)
 {
        dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
-                                     ctx->mc_buffer_bus & PAGE_MASK,
-                                     ctx->mc_buffer_bus & ~PAGE_MASK,
-                                     ctx->mc_completed, DMA_FROM_DEVICE);
+                                     ctx->mc.buffer_bus & PAGE_MASK,
+                                     ctx->mc.buffer_bus & ~PAGE_MASK,
+                                     ctx->mc.completed, DMA_FROM_DEVICE);
 
-       trace_isoc_inbound_multiple_completions(&ctx->base, ctx->mc_completed,
+       trace_isoc_inbound_multiple_completions(&ctx->base, ctx->mc.completed,
                                                FW_ISO_CONTEXT_COMPLETIONS_CAUSE_FLUSH);
 
-       ctx->base.callback.mc(&ctx->base,
-                             ctx->mc_buffer_bus + ctx->mc_completed,
+       ctx->base.callback.mc(&ctx->base, ctx->mc.buffer_bus + ctx->mc.completed,
                              ctx->base.callback_data);
-       ctx->mc_completed = 0;
+       ctx->mc.completed = 0;
 }
 
 static inline void sync_it_packet_for_cpu(struct context *context,
@@ -3028,7 +3029,7 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
 
        if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
                set_multichannel_mask(ohci, 0);
-               ctx->mc_completed = 0;
+               ctx->mc.completed = 0;
        }
 
        return &ctx->base;
@@ -3493,7 +3494,7 @@ static int ohci_flush_iso_completions(struct fw_iso_context *base)
                                flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_FLUSH);
                        break;
                case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
-                       if (ctx->mc_completed != 0)
+                       if (ctx->mc.completed != 0)
                                flush_ir_buffer_fill(ctx);
                        break;
                default: