media: vidtv: simplify PSI write function

The function vidtv_psi_ts_psi_write_into() initializes the
ts_header fields several times, and receives a struct
as argument, instead of using a pointer to struct.

Cleanup the function, in order to reduce its stack usage
and to avoid initializing the ts_header multiple times.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/test-drivers/vidtv/vidtv_psi.c b/drivers/media/test-drivers/vidtv/vidtv_psi.c
index fcdd617..2b56c64 100644 (file)
--- a/drivers/media/test-drivers/vidtv/vidtv_psi.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_psi.c
@@ -162,79 +162,75 @@ static void vidtv_psi_set_sec_len(struct vidtv_psi_table_header *h, u16 new_len)
  * manage the continuity_counter
  * add stuffing (i.e. padding bytes) after the CRC
  */
-static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args args)
+static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args *args)
 {
-
-       u32 nbytes_past_boundary = (args.dest_offset % TS_PACKET_LEN);
+       struct vidtv_mpeg_ts ts_header = {
+               .sync_byte = TS_SYNC_BYTE,
+               .bitfield = cpu_to_be16((args->new_psi_section << 14) | args->pid),
+               .scrambling = 0,
+               .payload = 1,
+               .adaptation_field = 0, /* no adaptation field */
+       };
+       u32 nbytes_past_boundary = (args->dest_offset % TS_PACKET_LEN);
        bool aligned = (nbytes_past_boundary == 0);
-       struct vidtv_mpeg_ts ts_header = {};
-       u32 remaining_len = args.len;
+       u32 remaining_len = args->len;
        u32 payload_write_len = 0;
        u32 payload_offset = 0;
        u32 nbytes = 0;
 
-       const u16 PAYLOAD_START = args.new_psi_section;
-
-       if (!args.crc && !args.is_crc)
+       if (!args->crc && !args->is_crc)
                pr_warn_ratelimited("Missing CRC for chunk\n");
 
-       if (args.crc)
-               *args.crc = dvb_crc32(*args.crc, args.from, args.len);
+       if (args->crc)
+               *args->crc = dvb_crc32(*args->crc, args->from, args->len);
 
-       if (args.new_psi_section && !aligned) {
+       if (args->new_psi_section && !aligned) {
                pr_warn_ratelimited("Cannot write a new PSI section in a misaligned buffer\n");
 
                /* forcibly align and hope for the best */
-               nbytes += vidtv_memset(args.dest_buf,
-                                      args.dest_offset + nbytes,
-                                      args.dest_buf_sz,
+               nbytes += vidtv_memset(args->dest_buf,
+                                      args->dest_offset + nbytes,
+                                      args->dest_buf_sz,
                                       TS_FILL_BYTE,
                                       TS_PACKET_LEN - nbytes_past_boundary);
        }
 
        while (remaining_len) {
-               nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;
+               nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;
                aligned = (nbytes_past_boundary == 0);
 
                if (aligned) {
                        /* if at a packet boundary, write a new TS header */
-                       ts_header.sync_byte = TS_SYNC_BYTE;
-                       ts_header.bitfield = cpu_to_be16((PAYLOAD_START << 14) | args.pid);
-                       ts_header.scrambling = 0;
-                       ts_header.continuity_counter = *args.continuity_counter;
-                       ts_header.payload = 1;
-                       /* no adaptation field */
-                       ts_header.adaptation_field = 0;
-
-                       /* copy the header */
-                       nbytes += vidtv_memcpy(args.dest_buf,
-                                              args.dest_offset + nbytes,
-                                              args.dest_buf_sz,
+                       ts_header.continuity_counter = *args->continuity_counter;
+
+                       nbytes += vidtv_memcpy(args->dest_buf,
+                                              args->dest_offset + nbytes,
+                                              args->dest_buf_sz,
                                               &ts_header,
                                               sizeof(ts_header));
                        /*
                         * This will trigger a discontinuity if the buffer is full,
                         * effectively dropping the packet.
                         */
-                       vidtv_ts_inc_cc(args.continuity_counter);
+                       vidtv_ts_inc_cc(args->continuity_counter);
                }
 
                /* write the pointer_field in the first byte of the payload */
-               if (args.new_psi_section)
-                       nbytes += vidtv_memset(args.dest_buf,
-                                              args.dest_offset + nbytes,
-                                              args.dest_buf_sz,
+               if (args->new_psi_section)
+                       nbytes += vidtv_memset(args->dest_buf,
+                                              args->dest_offset + nbytes,
+                                              args->dest_buf_sz,
                                               0x0,
                                               1);
 
                /* write as much of the payload as possible */
-               nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;
+               nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;
                payload_write_len = min(TS_PACKET_LEN - nbytes_past_boundary, remaining_len);
 
-               nbytes += vidtv_memcpy(args.dest_buf,
-                                      args.dest_offset + nbytes,
-                                      args.dest_buf_sz,
-                                      args.from + payload_offset,
+               nbytes += vidtv_memcpy(args->dest_buf,
+                                      args->dest_offset + nbytes,
+                                      args->dest_buf_sz,
+                                      args->from + payload_offset,
                                       payload_write_len);
 
                /* 'payload_write_len' written from a total of 'len' requested*/
@@ -246,12 +242,12 @@ static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args args)
         * fill the rest of the packet if there is any remaining space unused
         */
 
-       nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;
+       nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;
 
-       if (args.is_crc)
-               nbytes += vidtv_memset(args.dest_buf,
-                                      args.dest_offset + nbytes,
-                                      args.dest_buf_sz,
+       if (args->is_crc)
+               nbytes += vidtv_memset(args->dest_buf,
+                                      args->dest_offset + nbytes,
+                                      args->dest_buf_sz,
                                       TS_FILL_BYTE,
                                       TS_PACKET_LEN - nbytes_past_boundary);
 
@@ -275,7 +271,7 @@ static u32 table_section_crc32_write_into(struct crc32_write_args args)
        psi_args.is_crc             = true;
        psi_args.dest_buf_sz        = args.dest_buf_sz;
 
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        return nbytes;
 }
@@ -662,7 +658,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
        psi_args.dest_buf_sz        = args.dest_buf_sz;
        psi_args.crc                = args.crc;
 
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        switch (args.desc->type) {
        case SERVICE_DESCRIPTOR:
@@ -671,25 +667,25 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
                               sizeof_field(struct vidtv_psi_desc_service, provider_name_len);
                psi_args.from = &((struct vidtv_psi_desc_service *)args.desc)->service_type;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                psi_args.dest_offset = args.dest_offset + nbytes;
                psi_args.len = ((struct vidtv_psi_desc_service *)args.desc)->provider_name_len;
                psi_args.from = ((struct vidtv_psi_desc_service *)args.desc)->provider_name;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                psi_args.dest_offset = args.dest_offset + nbytes;
                psi_args.len = sizeof_field(struct vidtv_psi_desc_service, service_name_len);
                psi_args.from = &((struct vidtv_psi_desc_service *)args.desc)->service_name_len;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                psi_args.dest_offset = args.dest_offset + nbytes;
                psi_args.len = ((struct vidtv_psi_desc_service *)args.desc)->service_name_len;
                psi_args.from = ((struct vidtv_psi_desc_service *)args.desc)->service_name;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
                break;
 
        case NETWORK_NAME_DESCRIPTOR:
@@ -697,7 +693,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
                psi_args.len = args.desc->length;
                psi_args.from = ((struct vidtv_psi_desc_network_name *)args.desc)->network_name;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
                break;
 
        case SERVICE_LIST_DESCRIPTOR:
@@ -708,7 +704,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
                                       sizeof(struct vidtv_psi_desc_service_list_entry *);
                        psi_args.from = serv_list_entry;
 
-                       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+                       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                        serv_list_entry = serv_list_entry->next;
                }
@@ -720,32 +716,32 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
                psi_args.from = ((struct vidtv_psi_desc_short_event *)
                                  args.desc)->iso_language_code;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                psi_args.dest_offset = args.dest_offset + nbytes;
                psi_args.len = sizeof_field(struct vidtv_psi_desc_short_event, event_name_len);
                psi_args.from = &((struct vidtv_psi_desc_short_event *)
                                  args.desc)->event_name_len;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                psi_args.dest_offset = args.dest_offset + nbytes;
                psi_args.len = ((struct vidtv_psi_desc_short_event *)args.desc)->event_name_len;
                psi_args.from = ((struct vidtv_psi_desc_short_event *)args.desc)->event_name;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                psi_args.dest_offset = args.dest_offset + nbytes;
                psi_args.len = sizeof_field(struct vidtv_psi_desc_short_event, text_len);
                psi_args.from = &((struct vidtv_psi_desc_short_event *)args.desc)->text_len;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                psi_args.dest_offset = args.dest_offset + nbytes;
                psi_args.len = ((struct vidtv_psi_desc_short_event *)args.desc)->text_len;
                psi_args.from = ((struct vidtv_psi_desc_short_event *)args.desc)->text;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                break;
 
@@ -755,7 +751,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
                psi_args.len = args.desc->length;
                psi_args.from = &args.desc->data;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
                break;
        }
 
@@ -780,7 +776,7 @@ vidtv_psi_table_header_write_into(struct header_write_args args)
        psi_args.dest_buf_sz        = args.dest_buf_sz;
        psi_args.crc                = args.crc;
 
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        return nbytes;
 }
@@ -1014,7 +1010,7 @@ u32 vidtv_psi_pat_write_into(struct vidtv_psi_pat_write_args args)
                           sizeof(struct vidtv_psi_table_pat_program *);
                psi_args.dest_offset = args.offset + nbytes;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                p = p->next;
        }
@@ -1207,7 +1203,7 @@ u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args args)
        psi_args.dest_buf_sz        = args.buf_sz;
        psi_args.crc                = &crc;
 
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        while (table_descriptor) {
                /* write the descriptors, if any */
@@ -1232,7 +1228,7 @@ u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args args)
                                sizeof_field(struct vidtv_psi_table_pmt_stream, bitfield2);
                psi_args.dest_offset = args.offset + nbytes;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                stream_descriptor = stream->descriptor;
 
@@ -1360,7 +1356,7 @@ u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args args)
        psi_args.crc                = &crc;
 
        /* copy u16 network_id + u8 reserved)*/
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        while (service) {
                /* copy the services, if any */
@@ -1371,7 +1367,7 @@ u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args args)
                               sizeof(struct vidtv_psi_table_sdt_service *);
                psi_args.dest_offset = args.offset + nbytes;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                service_desc = service->descriptor;
 
@@ -1694,7 +1690,7 @@ u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args args)
        psi_args.dest_buf_sz        = args.buf_sz;
        psi_args.crc                = &crc;
 
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        while (table_descriptor) {
                /* write the descriptors, if any */
@@ -1718,7 +1714,7 @@ u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args args)
        psi_args.dest_offset = args.offset + nbytes;
        psi_args.pid = VIDTV_NIT_PID;
 
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        while (transport) {
                /* write the transport sections, if any */
@@ -1728,7 +1724,7 @@ u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args args)
                                sizeof_field(struct vidtv_psi_table_transport, bitfield);
                psi_args.dest_offset = args.offset + nbytes;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                transport_descriptor = transport->descriptor;
 
@@ -1907,7 +1903,7 @@ u32 vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args args)
        psi_args.dest_buf_sz        = args.buf_sz;
        psi_args.crc                = &crc;
 
-       nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+       nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
        while (event) {
                /* copy the events, if any */
@@ -1918,7 +1914,7 @@ u32 vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args args)
                               sizeof(struct vidtv_psi_table_eit_event *);
                psi_args.dest_offset = args.offset + nbytes;
 
-               nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+               nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
 
                event_descriptor = event->descriptor;