[SCSI] sun3: Remove commented out merge_contiguous_buffers (4d08e731) · Commits · 戴 / test

drivers/scsi/sun3_NCR5380.c

+0 −58

Original line number	Diff line number	Diff line
		@@ -49,13 +49,6 @@
		* inside the execution of NCR5380_intr(), leading to recursive
		* calls.
		*
		* - I've added a function merge_contiguous_buffers() that tries to
		* merge scatter-gather buffers that are located at contiguous
		* physical addresses and can be processed with the same DMA setup.
		* Since most scatter-gather operations work on a page (4K) of
		* 4 buffers (1K), in more than 90% of all cases three interrupts and
		* DMA setup actions are saved.
		*
		* - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
		* and USLEEP, because these were messing up readability and will never be
		* needed for Atari SCSI.
		@@ -459,47 +452,6 @@ static void free_all_tags( void )
		#endif /* SUPPORT_TAGS */


		/*
		* Function: void merge_contiguous_buffers(struct scsi_cmnd *cmd)
		*
		* Purpose: Try to merge several scatter-gather requests into one DMA
		* transfer. This is possible if the scatter buffers lie on
		* physical contiguous addresses.
		*
		* Parameters: struct scsi_cmnd *cmd
		* The command to work on. The first scatter buffer's data are
		* assumed to be already transferred into ptr/this_residual.
		*/

		static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
		{
		unsigned long endaddr;
		#if (NDEBUG & NDEBUG_MERGING)
		unsigned long oldlen = cmd->SCp.this_residual;
		int cnt = 1;
		#endif

		for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
		cmd->SCp.buffers_residual &&
		virt_to_phys(SGADDR(&(cmd->SCp.buffer[1]))) == endaddr; ) {

		MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
		SGADDR(&(cmd->SCp.buffer[1])), endaddr);
		#if (NDEBUG & NDEBUG_MERGING)
		++cnt;
		#endif
		++cmd->SCp.buffer;
		--cmd->SCp.buffers_residual;
		cmd->SCp.this_residual += cmd->SCp.buffer->length;
		endaddr += cmd->SCp.buffer->length;
		}
		#if (NDEBUG & NDEBUG_MERGING)
		if (oldlen != cmd->SCp.this_residual)
		MER_PRINTK("merged %d buffers from %p, new length %08x\n",
		cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
		#endif
		}

		/*
		* Function : void initialize_SCp(struct scsi_cmnd *cmd)
		*
		@@ -521,11 +473,6 @@ static __inline__ void initialize_SCp(struct scsi_cmnd *cmd)
		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
		cmd->SCp.ptr = (char *) SGADDR(cmd->SCp.buffer);
		cmd->SCp.this_residual = cmd->SCp.buffer->length;

		/* ++roman: Try to merge some scatter-buffers if they are at
		* contiguous physical addresses.
		*/
		// merge_contiguous_buffers( cmd );
		} else {
		cmd->SCp.buffer = NULL;
		cmd->SCp.buffers_residual = 0;
		@@ -2076,11 +2023,6 @@ static void NCR5380_information_transfer (struct Scsi_Host *instance)
		--cmd->SCp.buffers_residual;
		cmd->SCp.this_residual = cmd->SCp.buffer->length;
		cmd->SCp.ptr = SGADDR(cmd->SCp.buffer);

		/* ++roman: Try to merge some scatter-buffers if
		* they are at contiguous physical addresses.
		*/
		// merge_contiguous_buffers( cmd );
		INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
		HOSTNO, cmd->SCp.this_residual,
		cmd->SCp.buffers_residual);

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