From: Adrian Hunter Date: Fri, 16 Dec 2011 09:01:38 +0000 (+0200) Subject: dmaengine: intel_mid_dma: locking and freeing fixes X-Git-Tag: v3.3-rc1~19^2~7 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1fded07513ea57b5ee128958ff119e05588b7227;p=karo-tx-linux.git dmaengine: intel_mid_dma: locking and freeing fixes Two issues are fixed: 1. DMA descriptors are reused so when freeing lli structures that are linked to them, the pointer must be nulled. 2. midc_scan_descriptors() must be called with the channel lock held. Signed-off-by: Adrian Hunter Signed-off-by: Vinod Koul --- diff --git a/drivers/dma/intel_mid_dma.c b/drivers/dma/intel_mid_dma.c index 01929ed6659d..d4b961677e02 100644 --- a/drivers/dma/intel_mid_dma.c +++ b/drivers/dma/intel_mid_dma.c @@ -280,7 +280,8 @@ static void midc_dostart(struct intel_mid_dma_chan *midc, * callbacks but must be called with the lock held. */ static void midc_descriptor_complete(struct intel_mid_dma_chan *midc, - struct intel_mid_dma_desc *desc) + struct intel_mid_dma_desc *desc) + __releases(&midc->lock) __acquires(&midc->lock) { struct dma_async_tx_descriptor *txd = &desc->txd; dma_async_tx_callback callback_txd = NULL; @@ -311,6 +312,7 @@ static void midc_descriptor_complete(struct intel_mid_dma_chan *midc, pci_pool_free(desc->lli_pool, desc->lli, desc->lli_phys); pci_pool_destroy(desc->lli_pool); + desc->lli = NULL; } list_move(&desc->desc_node, &midc->free_list); midc->busy = false; @@ -490,7 +492,9 @@ static enum dma_status intel_mid_dma_tx_status(struct dma_chan *chan, ret = dma_async_is_complete(cookie, last_complete, last_used); if (ret != DMA_SUCCESS) { + spin_lock_bh(&midc->lock); midc_scan_descriptors(to_middma_device(chan->device), midc); + spin_unlock_bh(&midc->lock); last_complete = midc->completed; last_used = chan->cookie; @@ -566,6 +570,7 @@ static int intel_mid_dma_device_control(struct dma_chan *chan, pci_pool_free(desc->lli_pool, desc->lli, desc->lli_phys); pci_pool_destroy(desc->lli_pool); + desc->lli = NULL; } list_move(&desc->desc_node, &midc->free_list); }