2b1c6b21b5
As usual these patches were extracted and rebased from the raspberry pi repo: https://github.com/raspberrypi/linux/tree/rpi-4.4.y Also adds support for Raspberry Pi Compute Module 3 (untested). Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
107 lines
3.4 KiB
Diff
107 lines
3.4 KiB
Diff
From b61249080d5492fdb4bcf22e1672dc773a9bd95a Mon Sep 17 00:00:00 2001
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From: Phil Elwell <phil@raspberrypi.org>
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Date: Mon, 11 Apr 2016 12:50:58 +0100
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Subject: [PATCH] bcm2835-sdhost: Reset the clock in task context
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Since reprogramming the clock can now involve a round-trip to the
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firmware it must not be done at atomic context, and a tasklet
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is not a task.
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Signed-off-by: Phil Elwell <phil@raspberrypi.org>
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---
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drivers/mmc/host/bcm2835-sdhost.c | 25 ++++++++++++++++++-------
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1 file changed, 18 insertions(+), 7 deletions(-)
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--- a/drivers/mmc/host/bcm2835-sdhost.c
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+++ b/drivers/mmc/host/bcm2835-sdhost.c
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@@ -185,6 +185,7 @@ struct bcm2835_host {
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unsigned int debug:1; /* Enable debug output */
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unsigned int firmware_sets_cdiv:1; /* Let the firmware manage the clock */
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+ unsigned int reset_clock:1; /* Reset the clock fore the next request */
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/*DMA part*/
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struct dma_chan *dma_chan_rxtx; /* DMA channel for reads and writes */
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@@ -1505,6 +1506,7 @@ void bcm2835_sdhost_set_clock(struct bcm
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{
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int div = 0; /* Initialized for compiler warning */
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unsigned int input_clock = clock;
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+ unsigned long flags;
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if (host->debug)
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pr_info("%s: set_clock(%d)\n", mmc_hostname(host->mmc), clock);
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@@ -1544,13 +1546,17 @@ void bcm2835_sdhost_set_clock(struct bcm
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&msg, sizeof(msg));
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clock = max(msg[1], msg[2]);
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+ spin_lock_irqsave(&host->lock, flags);
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} else {
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+ spin_lock_irqsave(&host->lock, flags);
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if (clock < 100000) {
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/* Can't stop the clock, but make it as slow as
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* possible to show willing
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*/
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host->cdiv = SDCDIV_MAX_CDIV;
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bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
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+ mmiowb();
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+ spin_unlock_irqrestore(&host->lock, flags);
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return;
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}
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@@ -1605,6 +1611,11 @@ void bcm2835_sdhost_set_clock(struct bcm
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bcm2835_sdhost_write(host, clock/2, SDTOUT);
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host->mmc->actual_clock = clock;
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+ host->clock = input_clock;
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+ host->reset_clock = 0;
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+
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+ mmiowb();
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+ spin_unlock_irqrestore(&host->lock, flags);
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}
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static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq)
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@@ -1653,6 +1664,9 @@ static void bcm2835_sdhost_request(struc
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(mrq->data->blocks > host->pio_limit))
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bcm2835_sdhost_prepare_dma(host, mrq->data);
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+ if (host->reset_clock)
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+ bcm2835_sdhost_set_clock(host, host->clock);
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+
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spin_lock_irqsave(&host->lock, flags);
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WARN_ON(host->mrq != NULL);
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@@ -1731,14 +1745,12 @@ static void bcm2835_sdhost_set_ios(struc
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bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
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- if (!ios->clock || ios->clock != host->clock) {
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- bcm2835_sdhost_set_clock(host, ios->clock);
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- host->clock = ios->clock;
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- }
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-
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mmiowb();
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spin_unlock_irqrestore(&host->lock, flags);
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+
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+ if (!ios->clock || ios->clock != host->clock)
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+ bcm2835_sdhost_set_clock(host, ios->clock);
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}
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static struct mmc_host_ops bcm2835_sdhost_ops = {
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@@ -1810,7 +1822,7 @@ static void bcm2835_sdhost_tasklet_finis
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host->overclock_50--;
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pr_warn("%s: reducing overclock due to errors\n",
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mmc_hostname(host->mmc));
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- bcm2835_sdhost_set_clock(host,50*MHZ);
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+ host->reset_clock = 1;
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mrq->cmd->error = -EILSEQ;
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mrq->cmd->retries = 1;
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}
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@@ -1979,7 +1991,6 @@ static int bcm2835_sdhost_probe(struct p
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mmc->ops = &bcm2835_sdhost_ops;
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host = mmc_priv(mmc);
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host->mmc = mmc;
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- host->cmd_quick_poll_retries = 0;
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host->pio_timeout = msecs_to_jiffies(500);
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host->pio_limit = 1;
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host->max_delay = 1; /* Warn if over 1ms */
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