Commit 70f3ff43 authored by Russell King's avatar Russell King
Browse files

dmaengine: PL08x: get rid of write only pool_ctr and free_txd locking 



The free function says the pl08x lock should be taken before calling
it.  However, the DMA pool allocation/freeing is already properly
locked.  The only thing that would need this is pool_ctr, which
happens to be a write-only variable.

Let's get rid of this, and eliminate any need for additional locking
here.

Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent aa4afb75

drivers/dma/amba-pl08x.c

+0 −12
Original line number Diff line number Diff line
@@ -247,7 +247,6 @@ struct pl08x_dma_chan { 
 * @pd: platform data passed in from the platform/machine

 * @phy_chans: array of data for the physical channels

 * @pool: a pool for the LLI descriptors

 * @pool_ctr: counter of LLIs in the pool

 * @lli_buses: bitmask to or in to LLI pointer selecting AHB port for LLI

 * fetches

 * @mem_buses: set to indicate memory transfers on AHB2.
@@ -262,7 +261,6 @@ struct pl08x_driver_data { 
	struct pl08x_platform_data *pd;

	struct pl08x_phy_chan *phy_chans;

	struct dma_pool *pool;

	int pool_ctr;

	u8 lli_buses;

	u8 mem_buses;

};
@@ -821,8 +819,6 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x, 
		return 0;

	}



	pl08x->pool_ctr++;



	bd.txd = txd;

	bd.lli_bus = (pl08x->lli_buses & PL08X_AHB2) ? PL080_LLI_LM_AHB2 : 0;

	cctl = txd->cctl;
@@ -1038,18 +1034,14 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x, 
	return num_llis;

}



/* You should call this with the struct pl08x lock held */

static void pl08x_free_txd(struct pl08x_driver_data *pl08x,

			   struct pl08x_txd *txd)

{

	struct pl08x_sg *dsg, *_dsg;



	/* Free the LLI */

	if (txd->llis_va)

		dma_pool_free(pl08x->pool, txd->llis_va, txd->llis_bus);



	pl08x->pool_ctr--;



	list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {

		list_del(&dsg->node);

		kfree(dsg);
@@ -1090,8 +1082,6 @@ static void pl08x_desc_free(struct virt_dma_desc *vd) 
{

	struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);

	struct pl08x_dma_chan *plchan = to_pl08x_chan(vd->tx.chan);

	struct pl08x_driver_data *pl08x = plchan->host;

	unsigned long flags;



	if (!plchan->slave)

		pl08x_unmap_buffers(txd);
@@ -1099,9 +1089,7 @@ static void pl08x_desc_free(struct virt_dma_desc *vd) 
	if (!txd->done)

		pl08x_release_mux(plchan);



	spin_lock_irqsave(&pl08x->lock, flags);

	pl08x_free_txd(plchan->host, txd);

	spin_unlock_irqrestore(&pl08x->lock, flags);

}



static void pl08x_free_txd_list(struct pl08x_driver_data *pl08x,

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