From 8243e636c060fe7c10c9cf3bf53fdd2d48901525 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 3 Apr 2008 14:40:55 +0900 Subject: [PATCH] pata_ali: disable ATAPI DMA ATAPI DMA just doesn't work reliably on pata_ali. The IDE driver can do it but for some mysterious reason, pata_ali can't. This patch disables it by default and makes the driver whine during initialization. "pata_ali.atapi_dma" parameter is added so that user can bypass the workaround. Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- drivers/ata/pata_ali.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/drivers/ata/pata_ali.c b/drivers/ata/pata_ali.c index 8786455c901d..ce830fe3a362 100644 --- a/drivers/ata/pata_ali.c +++ b/drivers/ata/pata_ali.c @@ -36,6 +36,10 @@ #define DRV_NAME "pata_ali" #define DRV_VERSION "0.7.5" +int ali_atapi_dma = 0; +module_param_named(atapi_dma, ali_atapi_dma, int, 0644); +MODULE_PARM_DESC(atapi_dma, "Enable ATAPI DMA (0=disable, 1=enable)"); + /* * Cable special cases */ @@ -269,6 +273,27 @@ static void ali_set_dmamode(struct ata_port *ap, struct ata_device *adev) } } +/** + * ali_warn_atapi_dma - Warn about ATAPI DMA disablement + * @adev: Device + * + * Whine about ATAPI DMA disablement if @adev is an ATAPI device. + * Can be used as ->dev_config. + */ + +static void ali_warn_atapi_dma(struct ata_device *adev) +{ + struct ata_eh_context *ehc = &adev->link->eh_context; + int print_info = ehc->i.flags & ATA_EHI_PRINTINFO; + + if (print_info && adev->class == ATA_DEV_ATAPI && !ali_atapi_dma) { + ata_dev_printk(adev, KERN_WARNING, + "WARNING: ATAPI DMA disabled for reliablity issues. It can be enabled\n"); + ata_dev_printk(adev, KERN_WARNING, + "WARNING: via pata_ali.atapi_dma modparam or corresponding sysfs node.\n"); + } +} + /** * ali_lock_sectors - Keep older devices to 255 sector mode * @adev: Device @@ -283,6 +308,7 @@ static void ali_set_dmamode(struct ata_port *ap, struct ata_device *adev) static void ali_lock_sectors(struct ata_device *adev) { adev->max_sectors = 255; + ali_warn_atapi_dma(adev); } /** @@ -294,6 +320,18 @@ static void ali_lock_sectors(struct ata_device *adev) static int ali_check_atapi_dma(struct ata_queued_cmd *qc) { + if (!ali_atapi_dma) { + /* FIXME: pata_ali can't do ATAPI DMA reliably but the + * IDE alim15x3 driver can. I tried lots of things + * but couldn't find what the actual difference was. + * If you got an idea, please write it to + * linux-ide@vger.kernel.org and cc htejun@gmail.com. + * + * Disable ATAPI DMA for now. + */ + return -EOPNOTSUPP; + } + /* If its not a media command, its not worth it */ if (atapi_cmd_type(qc->cdb[0]) == ATAPI_MISC) return -EOPNOTSUPP; @@ -359,6 +397,7 @@ static struct ata_port_operations ali_20_port_ops = { .tf_load = ata_tf_load, .tf_read = ata_tf_read, + .check_atapi_dma = ali_check_atapi_dma, .check_status = ata_check_status, .exec_command = ata_exec_command, .dev_select = ata_std_dev_select, @@ -438,6 +477,7 @@ static struct ata_port_operations ali_c5_port_ops = { .check_status = ata_check_status, .exec_command = ata_exec_command, .dev_select = ata_std_dev_select, + .dev_config = ali_warn_atapi_dma, .freeze = ata_bmdma_freeze, .thaw = ata_bmdma_thaw, -- 2.20.1